Lucas Peterson, Respondent, vs. City of Minneapolis, Self-Insured, Relator

Minnesota Supreme Court

Lucas Peterson, Respondent, vs. City of Minneapolis, Self-Insured, Relator

Opinion

                                STATE OF MINNESOTA

                                 IN SUPREME COURT

                                      A24-1205


Workers’ Compensation Court of Appeals                                         Gaïtas, J.
                                                  Concurring in part, dissenting in part,
                                                                Moore, III, Thissen, JJ.
Lucas Peterson,

                    Respondent,

vs.                                                                Filed: July 16, 2025
                                                             Office of Appellate Courts
City of Minneapolis, Self-Insured,

                    Relator.


                               ________________________


Ashley N. Biermann, Alexa R. Hottle, Meshbesher & Spence, Minneapolis, Minnesota, for
respondent.

Jeffrey J. Lindquist, Anthony Gabor, Justine K. Wagner, Gries Lenhardt Allen, P.L.L.P.,
Saint Michael, Minnesota, for relator.

Paul A. Merwin, Patricia Y. Beety, General Counsel, League of Minnesota Cities, Saint
Paul, Minnesota, for amicus curiae League of Minnesota Cities.

Timothy P. Jung, Lind Jensen Sullivan & Peterson, Minneapolis, Minnesota, for amicus
curiae Minnesota Counties Intergovernmental Trust.

Joshua W. Laabs, Minnetonka, Minnesota; and

Lindsey M. Rowland, Meuser, Yackley & Rowland, Eden Prairie, Minnesota, for amicus
curiae Minnesota Association for Justice.

                               ________________________



                                          1

SYLLABUS

      1.     The Workers’ Compensation Court of Appeals did not err in affirming the

compensation judge’s finding that the employee has a compensable mental injury because

that finding is not manifestly contrary to the evidence, which included testimony by a

licensed professional psychologist that, based on the most recent edition of the Diagnostic

and Statistical Manual of Mental Disorders, the employee has a present diagnosis of

post-traumatic stress disorder (PTSD).

      2.     The Workers’ Compensation Court of Appeals erred in addressing the

employee’s argument that he was entitled to compensation benefits for a diagnosis of other

specified trauma and stressor-related disorder (OSTD) as a consequential mental injury of

PTSD because that issue was moot given the record here, where the employee’s expert

psychologist opined that the employee’s OSTD diagnosis was “subthreshold PTSD” and

the Workers’ Compensation Court of Appeals decided that the employee is entitled to

compensation benefits for a present diagnosis of PTSD.

      3.     The Workers’ Compensation Court of Appeals did not err in affirming the

compensation judge’s award of a penalty for frivolous denial of primary liability.

      Affirmed in part and reversed in part.

OPINION

GAÏTAS, Justice.

      In this case, we are asked to decide whether the Workers’ Compensation Court of

Appeals (WCCA) erred in affirming the compensation judge’s determination that the

employee, Lucas Peterson, is entitled to workers’ compensation benefits under Minnesota


                                               2
Statutes section 176.66 (2024) for a mental impairment. We are further asked to decide

whether the WCCA erred in affirming the compensation judge’s award of penalties against

the employer, City of Minneapolis. The City argues that the WCCA committed errors of

law by (1) affirming the compensation judge’s determination that Peterson is entitled to

workers’ compensation benefits for a present diagnosis of post-traumatic stress disorder

(PTSD); (2) sua sponte referring the case back to the compensation judge for a finding

regarding Peterson’s claim for benefits based on a diagnosis of other specified trauma and

stressor-related disorder (OSTD) as a consequential mental injury of PTSD; (3) affirming

the compensation judge’s determination following the referral that Peterson is entitled to

workers’ compensation benefits for OSTD as a consequential mental injury of PTSD; and

(4) affirming the compensation judge’s award of penalties against the City for frivolous

denial of liability. We conclude that the WCCA did not err by affirming the compensation

judge’s determination that Peterson is entitled to workers’ compensation benefits for a

present diagnosis of PTSD or by affirming the award of penalties, and thus, we affirm its

decision in part. But because the WCCA erred when it decided that Peterson is also entitled

to workers’ compensation benefits for OSTD, even though that issue was moot, we reverse

in part.

                                         FACTS

       Respondent Lucas Peterson worked as a police officer for relator City of

Minneapolis for 22 years. In 2021, Peterson informed the City that he could no longer




                                            3
serve as a police officer due to PTSD,1 and he sought workers’ compensation benefits. The

City denied liability, and Peterson filed a claim petition. Following a hearing, a workers’

compensation judge ruled that Peterson was entitled to benefits and awarded penalties

against the City for frivolously denying benefits. The WCCA affirmed. In this appeal, the

City challenges the decision of the WCCA.

       Based on the record before us, the relevant facts are as follows. The City of

Minneapolis hired Peterson in 1999 as a community service officer. Before beginning his

employment, Peterson underwent a pre-employment mental health exam by a licensed

psychologist. The psychologist reported that Peterson “[did] not appear to have any

significant personality or emotional problems.” After serving as a community service

officer for approximately one year, the City hired Peterson to be a patrol officer. He

underwent another pre-employment mental health exam.               Again, the evaluating

psychologist reported that Peterson “[did] not appear to have any significant personality or

emotional problems.”

       In 2003, Peterson joined the Minneapolis Police Department’s special weapons and

tactics (SWAT) team. He later served as a sergeant and supervisor with the SWAT team.

       During Peterson’s 22 years with the police department, he experienced numerous

traumatic events. Peterson estimated that he responded to 30 to 50 homicide calls—five

or six involving the death of a child. He responded to a mass shooting with an active


1
       PTSD is a mental health disorder that can develop after an individual is exposed to
traumatic events. Am. Psychiatric Ass’n, Diagnostic and Statistical Manual of Mental
Disorders, Text Revision 301–03 (5th ed. 2022) (DSM-5-TR). Symptom presentation and
severity vary widely depending on the individual. See id.

                                             4
shooter. And he was present for 10 to 15 officer-involved shootings. According to

Peterson, he feared for his life and the lives of others on multiple occasions while

performing his job.

       In March 2021, Peterson began twice-weekly therapy with a counselor. At the

therapist’s recommendation, Peterson visited a physician, who diagnosed him with anxiety

related to his work. Following that diagnosis, Peterson hired a lawyer to pursue workers’

compensation benefits.

       A licensed psychologist, Dr. John Cronin, performed an extensive evaluation of

Peterson in May and June 2021. In a report dated June 21, 2021, Dr. Cronin diagnosed

Peterson with PTSD and recommended that Peterson stop working as a police officer.

Peterson notified the City that he was unable to work as of May 2021, due to PTSD, and

he sought workers’ compensation benefits.

       In September 2021, the City denied primary liability for Peterson’s PTSD claim,

maintaining that Peterson did not meet the criteria for a PTSD diagnosis and that any

presumption of compensability did not apply. See 
Minn. Stat. § 176.011
, subd. 15(e)

(2024)2 (establishing a presumption—for certain active-duty employees, including police

officers—that PTSD is “an occupational disease and shall be presumed to have been due

to the nature of employment” so long as the employee “had not been diagnosed with


2
       Throughout this opinion, we apply the statutes in effect on Peterson’s date of injury,
May 26, 2021, which is the date Peterson stopped working as a police officer. See Joyce
v. Lewis Bolt & Nut Co., 
412 N.W.2d 304, 307
 (Minn. 1987) (explaining that workers’
compensation cases are governed by “the law in effect on the date of the controlling event,”
which is the date of “the most recent occurrence of a compensable personal injury”). The
parties do not dispute the date of injury.

                                             5
[PTSD] previously”). To rebut any presumption of compensability, the City alleged that

Peterson had a history of mental health conditions before his employment. See 
id.

(providing that the presumption “may be rebutted by substantial factors brought by the

employer or insurer”). The City did not investigate Peterson’s claim at that time.

       Peterson filed a claim petition with the Office of Administrative Hearings on

November 8, 2021, claiming entitlement to workers’ compensation benefits as a result of

a work-related PTSD diagnosis with a May 26, 2021 date of injury.

       The City hired Dr. Kenneth Ray Young, a licensed psychologist, to perform

an independent psychological examination of Peterson on March 12, 2022. Dr. Young

issued a report concluding that Peterson did not satisfy the criteria for a PTSD diagnosis or

any other mental health disorder under the Diagnostic and Statistical Manual of Mental

Disorders (5th ed. 2013) (DSM-5).3

       At the request of Peterson’s attorney, another licensed psychologist, Dr. Kasey

Aleknavicius, performed an independent psychiatric evaluation of Peterson on May 25,

2022, and issued a written report. Her written report stated that Peterson did not presently

meet the criteria for a PTSD diagnosis under the DSM-5, “likely due to his participation in

treatment during the last year.” But Dr. Aleknavicius’s report determined that Peterson did


3
       The Diagnostic and Statistical Manual of Mental Disorders (DSM) is a handbook
used by medical professionals to assist in the diagnosis of patients’ mental disorders. See
Smith v. Carver County, 
931 N.W.2d 390, 397
 (Minn. 2019).
       PTSD is defined by Minnesota statute as “the condition as described in the most
recently published edition of the Diagnostic and Statistical Manual of Mental Disorders by
the American Psychiatric Association.” 
Minn. Stat. § 176.011
, subd. 15(d) (2020). It is
the only mental impairment recognized as an occupational disease for the purposes of
Minnesota’s workers’ compensation law. See 
id.

                                             6
previously meet the full criteria for PTSD under the DSM-5, citing to an assessment dated

May 3, 2021, which diagnosed Peterson with PTSD, and Dr. Cronin’s June 21, 2021 report.

Dr. Aleknavicius concluded that Peterson currently met the DSM-5 criteria for OSTD,

which her report characterized as “subthreshold PTSD.” Dr. Aleknavicius opined in her

report that Peterson’s OSTD was a “direct result” of Peterson’s “previous PTSD

diagnosis.” Her report noted that the diagnosis of OSTD “is consistent with repeated

exposure to aversive details of trauma, witnessing trauma as it occurred to others, and

fearing for his own safety, and that of others, while performing his duties as a police officer

for the [Minneapolis Police Department].” Dr. Aleknavicius’s report further explained

that, although Peterson’s consistent mental health treatment helped “reliev[e] the

severity/frequency of some symptoms,” he was still experiencing “persisting symptoms”

that “continue[d] to result in significant distress and impairment in his occupational and

social functioning.”

       Following Dr. Aleknavicius’s report, Peterson filed an amended claim petition on

November 7, 2022.       The amended petition claimed that Peterson was entitled to

compensation benefits as a result of the May 26, 2021 PTSD injury. And it alleged a new

claim of consequential injury in the nature of OSTD.

       Proceedings Before the Compensation Judge

       The compensation judge held a hearing on March 23 and April 27, 2023, to

determine Peterson’s eligibility for workers’ compensation benefits.

       Peterson and his wife testified on the first day of the hearing. During Peterson’s

testimony, he described his work as a Minneapolis police officer, the traumatic incidents


                                              7
he experienced at work, and the onset and exacerbation of his mental health symptoms. He

testified that he has improved with therapy, but he still has poor concentration, negative

thoughts, loss of empathy, sleep disturbance, anxiety, depression, feelings of isolation, and

unregulated anger and emotions. Peterson’s wife testified that she has been married to

Peterson since 2006. She explained that she observed significant changes in Peterson’s

demeanor and behavior over the course of his work as a police officer.

       On the second day of the hearing, Dr. Aleknavicius testified on behalf of Peterson,

and Dr. Young testified on behalf of the City. They offered diverging opinions about

Peterson’s mental health.

       Dr. Aleknavicius described her process of evaluating Peterson and her conclusions.

She testified that, in her opinion, “the stressors that [Peterson] . . . experienced and had

exposure to in his career [were] more than [she] would say [w]as typical in the first

responders that [she had] assessed or treated.”

       Dr. Aleknavicius agreed that Peterson met the criteria for PTSD when he was

initially diagnosed in May 2021. But she testified that when she evaluated Peterson in

May 2022 using the DSM-5—the version of the DSM in effect at that time—she

determined that Peterson no longer satisfied the criteria for a diagnosis of PTSD. This was

because some of Peterson’s symptoms had improved due to therapy and treatment, and

they no longer met “the threshold during the last month to be endorsed as a current

symptom of PTSD.” Dr. Aleknavicius testified that an OSTD diagnosis “is a DSM-5

diagnosis that was added as a way to describe other individuals who don’t quite meet the

full criteria for PTSD.” She explained that PTSD can “cause” OSTD, describing Peterson’s


                                             8
OSTD as “subthreshold PTSD” caused by “persisting PTSD symptoms.” Dr. Aleknavicius

elaborated that, in such cases, “the PTSD hasn’t quite resolved itself, but it’s not meeting

the full criteria. So what happens is that as a result, [the person] now ha[s] [OSTD].” Dr.

Aleknavicius testified that, despite Peterson’s improvement, he remained impaired when

she evaluated him because other symptoms persisted, including avoidance of

trauma-related reminders and intrusive experiences. According to Dr. Aleknavicius, at the

time of her evaluation, Peterson’s symptoms were “subthreshold . . . not quite meeting full

criteria and full threshold for PTSD.” Therefore, her written evaluation diagnosed Peterson

with OSTD, “specifically specifying subthreshold PTSD.”

       However, Dr. Aleknavicius testified that after she prepared her written report, she

learned that there was a “text revision” of the DSM-5.4 According to Dr. Aleknavicius, the

most recent version of the DSM was no longer the DSM-5, which she had relied on at the

time of Peterson’s evaluation and her written report. Instead, at the time of the hearing

before the compensation judge in 2023, the most recent version was the DSM-5-TR. See

Am. Psychiatric Ass’n, Diagnostic and Statistical Manual of Mental Disorders, Text

Revision (5th ed. 2022) (DSM-5-TR). Dr. Aleknavicius testified that the DSM-5-TR did

not include changes to the diagnostic criteria, but it did include changes to the text. And

given changes to the text in the PTSD section of the DSM-5-TR, Dr. Aleknavicius revised




4
       Dr. Aleknavicius testified that the DSM-5-TR was published in March 2022, which
was a few months before her evaluation of Peterson.

                                             9
her diagnosis of Peterson to be a present diagnosis of PTSD.5 She explained that the text

revision to the PTSD section states that for a “lifetime diagnosis” of PTSD “there must be

a period of time lasting more than one month during which criterion B, C, D, and E have

all been met for the same one[-]month period of time.”6 Dr. Aleknavicius testified that,

because Peterson previously met all criteria for a diagnosis of PTSD for more than a one-

month period, and “[h]e continues to meet some but not all of the criteria for PTSD,” he

has a present diagnosis of PTSD “based on the lifetime diagnosis” provision in the

DSM-5-TR.

      In Dr. Aleknavicius’s opinion, Peterson should never return to a job in law

enforcement in any capacity. She testified that Peterson would be at “significant risk for

additional trauma or exposure and worsening of [his] symptoms or reoccurrence of [his]

symptoms.” However, Dr. Aleknavicius stated, “The only work restriction I issued was

not to return to work in law enforcement as a first responder or in any safety sensitive

position.” She opined that Peterson could return to full-time work in another field. Dr.

Aleknavicius recommended that Peterson continue to treat his ongoing symptoms.



5
        The City objected to Dr. Aleknavicius’s revised opinion testimony. But the
compensation judge permitted it, in part, because the City’s expert, Dr. Young, appeared
at the hearing and would have an opportunity to rebut Dr. Aleknavicius’s testimony.
6
        Criterion B concerns intrusion symptoms associated with the traumatic event(s)
(e.g., recurrent distressing dreams or memories, dissociative flashbacks). Am. Psychiatric
Ass’n, Diagnostic and Statistical Manual of Mental Disorders, Text Revision 301 (5th ed.
2022). Criterion C concerns persistent avoidance of stimuli associated with the traumatic
event(s). 
Id. at 302
. Criterion D concerns negative changes in thinking and mood
associated with the traumatic event(s). 
Id.
 Criterion E includes trauma-related reactivity,
such as irritability, aggression, or risky behavior. 
Id.

                                            10
       The City’s expert, Dr. Young, testified that, in his opinion, Peterson “didn’t meet

criteria for any mental health disorder” at the time of his evaluation. He also disagreed

with the two experts who had diagnosed Peterson with PTSD. Dr. Young criticized the

methodologies and conclusions of both Dr. Aleknavicius and Dr. Cronin, the psychologist

who evaluated Peterson in 2021.

       As to his own evaluation of Peterson, Dr. Young observed that Peterson

demonstrated no difficulty discussing the traumatic events he had experienced as a police

officer. In his view this was atypical for someone with PTSD. He acknowledged that

Peterson had some symptoms related to PTSD. But he did not believe that Peterson

satisfied the criteria for a PTSD diagnosis.

       Dr. Young also disagreed with Dr. Aleknavicius’s testimony that, given the new

language in the DSM-5-TR concerning “lifetime PTSD,” Peterson satisfied the criteria for

a present diagnosis of PTSD. He testified that “lifetime PTSD” is not a diagnosis. Rather,

the term refers to “looking at . . . lifetime prevalence of PTSD or if someone has ever met

criteria for PTSD over the course of their lifetime.”

       Finally, Dr. Young disagreed with Dr. Aleknavicius’s opinions regarding OSTD.

He testified that Peterson did not suffer from OSTD. And he disagreed that PTSD causes

OSTD. Dr. Young explained that “trauma-related disorders are more on a spectrum, not

one thing kind of causing another thing.” According to Dr. Young, the DSM-5 requires a

“rule-out”—one trauma disorder does not cause another, but instead, a practitioner must

diagnose one such disorder or another.




                                               11
       Following the hearing, the compensation judge issued his findings and order. The

compensation judge found the testimony of Peterson and his wife to be credible. According

to the compensation judge, Peterson experienced nine specific traumatic events while

working as a police officer. Following these events, Peterson “experienced numbness,

disconnection, lack of empathy, isolation, anger, detachment, and depression.” The

compensation judge found that Peterson had been diagnosed with PTSD by several

professionals.   As to the opinions of the experts who testified at the hearing, the

compensation judge credited the testimony of Dr. Aleknavicius. The compensation judge

found that her opinions were more persuasive than Dr. Young’s, and the compensation

judge explained the basis for this finding.7       Accordingly, the compensation judge

determined that Peterson “continued to meet the diagnosis of PTSD through the second

day of [the] hearing as that condition is described in the most recently published edition of

the DSM-5-TR.” The compensation judge concluded that the City had failed to rebut the

statutory presumption of compensability, and thus Peterson was entitled to workers’

compensation benefits.




7
       According to the compensation judge, Dr. Aleknavicius’s opinions were more
persuasive than Dr. Young’s because (1) Peterson “credibly testified to the gravity of the
traumatic events he encountered in his job”; (2) Peterson “credibly testified to his ongoing
symptoms”; (3) Peterson’s wife “credibly testified” to Peterson’s “ongoing symptoms”;
(4) Dr. Aleknavicius’s opinions are “mostly consistent” with assessments of four other
professionals who interacted with Peterson; (5) “Dr. Aleknavicius’[s] opinions comport
with [Peterson’s] credible testimony and history of treatment”; and (6) Dr. Young
acknowledged that Peterson had experienced traumatic events that would satisfy the first
diagnostic criterion for PTSD.

                                             12
       Furthermore, the compensation judge found that the City had frivolously denied

payment of disability benefits between June 21, 2021, and March 12, 2022—between the

time of Peterson’s PTSD diagnosis by Dr. Cronin and when the City opposed the diagnosis

following Dr. Young’s examination of Peterson. The compensation judge imposed a

30 percent statutory penalty for the frivolous denial of payment during this period. See

Minn. Stat. § 1
 76.225, subd. 1(5) (2024).

       Proceedings Before the WCCA

       The City appealed the compensation judge’s decision to the WCCA. Before the

WCCA, the City challenged the compensation judge’s (1) finding that Peterson had a

present PTSD diagnosis and (2) award of a penalty for the City’s frivolous denial of

primary liability.

       Following oral argument, the WCCA filed an order of referral directing the

compensation judge to make findings based on the existing record regarding whether

Peterson had also experienced a consequential mental injury. The order stated:

       Although the [consequential mental injury] issue was prefaced with ‘in the
       alternative,’ we find it necessary for the [referred] issue listed above to be
       determined by the compensation judge before this court may make a decision
       on the employer and insurer’s appeal. This will promote fair and efficient
       administration of the appeal for all parties.

       Subsequently, the compensation judge filed findings on referral from the WCCA.

The compensation judge again found that “[t]he findings and opinions of Dr. Kasey

Aleknavicius were more persuasive than those of Dr. Ken Young.” Additionally, the

compensation judge found that Peterson “sustained a consequential mental health condition

in the nature of [OSTD] as a substantial result of the original PTSD diagnosis.”


                                             13
       The WCCA affirmed the decision of the compensation judge in its entirety.

Peterson v. City of Minneapolis, No. WC23-6527, 
2024 WL 3363123
, at *1 (Minn. WCCA

June 28, 2024). It determined that substantial evidence supported the compensation

judge’s finding that Peterson has a present diagnosis of PTSD. 
Id. at *15
. The WCCA

also determined as a matter of law that once an employee has established a compensable

PTSD injury, any mental health condition substantially caused by, aggravated by, or

accelerated by the PTSD diagnosis is also compensable as a consequential injury, and that

it was reasonable for the compensation judge to find that Peterson’s OSTD condition was

compensable. 
Id. at *17
. Finally, the WCCA determined that the compensation judge did

not clearly err in finding that the City had frivolously denied primary liability, and it

affirmed the compensation judge’s award of a penalty. 
Id. at *18
.

       The City appealed the WCCA’s decision by writ of certiorari.8

                                       ANALYSIS

                                            I.

       We first consider whether the WCCA erred in affirming the compensation judge’s

decision that Peterson was entitled to workers’ compensation benefits for PTSD. The City

argues that the WCCA “committed errors of law when it determined that an individual who

no longer meets the criteria for PTSD can still qualify for benefits simply because he once

had PTSD.” Peterson responds that the City’s argument does not concern an error of law,


8
      In addition to the parties’ briefs, we received amicus curiae briefs from League of
Minnesota Cities, Minnesota Counties Intergovernmental Trust, and Minnesota
Association for Justice. The Court appreciates the assistance of these organizations in our
consideration of the issues presented here.

                                            14
but is instead a challenge to the factual findings of the compensation judge and the WCCA

decision upholding those findings. He points out that an expert testified that he has a

present diagnosis of PTSD based on the most recent edition of the DSM, and thus, the

record supports the finding that he is entitled to workers’ compensation for PTSD.

                                            A.

        To determine the applicable standard of review, we must initially decide whether

the City’s argument presents a question of law or a question of fact. We begin our analysis

of this issue by considering the relevant law and the decisions of the lower courts in this

case.

        PTSD is the only “mental impairment” recognized by the Workers’ Compensation

Act. 
Minn. Stat. § 176.011
, subd. 15(d) (2024). Under Minnesota law, when a police

officer experiences PTSD and has not been previously diagnosed with this condition, there

is a presumption that it is an occupational disease “due to the nature of employment.” 
Id.,

subd. 15(e). A compensation judge can award compensation for PTSD if the employee

proves that “(1) a psychiatrist or psychologist has diagnosed the employee with PTSD, and

(2) the professional based the employee’s diagnosis on the latest version of the DSM.”

Chrz v. Mower County, 
986 N.W.2d 481
, 485 (Minn. 2023). When medical experts offer

divergent diagnoses, the compensation judge must first decide whether the experts’

opinions “have adequate foundation.”       Tea v. Ramsey County, 5 N.W.3d 114, 120

(Minn. 2024) (citation omitted) (internal quotation marks omitted). If there is adequate

foundation, the compensation judge must then “decide which of the professional diagnoses

is more credible and persuasive.” 
Id.
 (citation omitted) (internal quotation marks omitted).


                                            15
       Here,   two    licensed   psychologists    performed    independent    psychological

examinations of Peterson and offered conflicting opinions as to whether he had a present

diagnosis of PTSD. Peterson’s expert, Dr. Aleknavicius, testified that Peterson had a

present diagnosis of PTSD under the most recent version of the DSM. The City’s expert,

Dr. Young, testified that Peterson did not meet the diagnostic criteria for PTSD or any other

mental health disorder.

       The compensation judge found that Dr. Aleknavicius’s opinions were more credible

and persuasive than Dr. Young’s opinions and explained this finding.            Further, the

compensation judge adopted Dr. Aleknavicius’s opinion that Peterson “has PTSD as

described in the most recently published edition of the DSM.” On review, the WCCA

affirmed the compensation judge’s factual findings.           Peterson, 
2024 WL 3363123
,

at *14–15. It determined that substantial evidence in the record—Dr. Aleknavicius’s

testimony—supported the compensation judge’s ultimate factual finding that Peterson has

a current PTSD diagnosis based on the most recent version of the DSM. 
Id. at *15
.

       The decisions below were based on the compensation judge’s factual findings as to

“which of the professional diagnoses [was] more credible and persuasive.” Tea, 5 N.W.3d

at 120 (citation omitted) (internal quotation marks omitted). To decide whether the

compensation judge and the WCCA erred in finding that Peterson has a present PTSD

diagnosis that entitles him to workers’ compensation benefits, our review must focus on

the factual findings regarding the experts’ testimony. Thus, we apply our standard of

review for factual findings. See 
id.
 at 119–21 (applying the standard of review for factual




                                             16
findings in reviewing the WCCA’s affirmance of the compensation judge’s finding that the

employee has compensable PTSD).

          In a workers’ compensation case, our standard of review for factual findings

depends on “whether a conflict exists between the findings of the workers’ compensation

court and the findings of the WCCA.”          Lagasse v. Horton, 
982 N.W.2d 189
, 201

(Minn. 2022).      When no conflict exists—as here, where the WCCA affirmed the

compensation judge’s factual findings—we “view the facts in the light most favorable to

the findings and must uphold those findings unless they are ‘manifestly contrary to the

evidence.’ ” Tea, 5 N.W.3d at 119 (quoting Schmidt v. Wal-Mart Stores, 
988 N.W.2d 124
,

129 (Minn. 2023)). A finding is manifestly contrary to evidence when the evidence

“clearly requires reasonable minds to adopt a contrary conclusion.” Lagasse, 982 N.W.2d

at 202.

                                             B.

          Applying this standard of review, we now consider whether the WCCA erred in

affirming the compensation judge’s finding that Peterson has compensable PTSD. As

noted, Dr. Aleknavicius explained during her testimony that Peterson no longer met all of

the diagnostic criteria for PTSD when she evaluated him because some of his symptoms

had improved over time with treatment. But Dr. Aleknavicius testified that a text revision

to the DSM in March 2022 clarified that, when Criteria B, C, D, and E are simultaneously

met for more than one month, they are considered satisfied for an individual’s lifetime.

Dr. Aleknavicius testified that Peterson previously met all of the criteria for PTSD for more

than one month and that he presently satisfied the other criteria necessary for a PTSD


                                             17
diagnosis. Thus, she concluded, Peterson presently has PTSD as defined by the most recent

version of the DSM.

      Based on this evidence in the record, we conclude that the finding that Peterson has

a present PTSD diagnosis is not manifestly contrary to the evidence. Stated differently,

the evidence presented does not clearly require “reasonable minds to adopt a contrary

conclusion.” Lagasse, 982 N.W.2d at 202. Although the City introduced conflicting

evidence regarding Peterson’s mental health, the compensation judge was not required to

accept it. Instead, it had authority to decide which expert’s testimony was “more credible

and persuasive.” Tea, 5 N.W.3d at 120 (citation omitted) (internal quotation marks

omitted).   The compensation judge determined that Dr. Aleknavicius’s testimony

prevailed. Because the compensation judge’s choice was not clearly unreasonable, the

WCCA’s affirmance of the compensation judge’s finding is not manifestly contrary to the

evidence.

      The City argues that this case is “strikingly similar” to Chrz, where we affirmed the

WCCA’s decision that an employee who was previously—but not currently—diagnosed

with PTSD was not entitled to workers’ compensation benefits. 986 N.W.2d at 487. In

Chrz, two psychologists testified before the compensation judge that the employee no

longer met the diagnostic criteria for PTSD. Id. at 483–84. We agreed with the WCCA

that only a present diagnosis of PTSD qualifies as an occupational disease under the

Workers’ Compensation Act. Id. at 486. Here, however, an expert testified that Peterson

did presently meet the diagnostic criteria for PTSD. And the compensation judge expressly

credited that testimony over conflicting expert testimony that Peterson did not meet the


                                           18
criteria for PTSD or any other mental health disorder. Thus, our decision in Chrz does not

control.

       The City also challenges the substance of Dr. Aleknavicius’s opinions regarding the

revisions in the DSM-TR-5. It argues that the DSM-TR-5 is not a “new edition” of the

DSM because it is still the “Fifth Edition.”9        It contends that Dr. Aleknavicius

misinterpreted the revised text of the DSM-TR-5, which includes the language regarding

“lifetime PTSD.” And it argues that the opinions of its expert, Dr. Young, are more

consistent with the text of the DSM. But these arguments are challenges to the factual

findings of the compensation judge, which we have already determined are not clearly

unreasonable.   Moreover, the City’s arguments suggest that it is appropriate for a

compensation judge or the WCCA to make its own diagnosis of an employee by applying

the DSM or to perform a “legalistic analysis” of the DSM. In Tea, however, we clarified

that a compensation judge’s factual findings “must be in relation to evidence offered by

another medical professional—not based upon the judge’s own application of the DSM

criteria to the employee’s symptoms.” 5 N.W.3d at 122.

       Finally, the City suggests that the compensation judge erred by failing to

acknowledge in its factual findings Dr. Young’s “interpretation” of the relevant revisions

to the DSM-5-TR. It further contends that the WCCA’s finding that Dr. Young “offered

no other interpretation of the new text” is manifestly contrary to the evidence. Peterson,

2024 WL 3363123
, at *13. We disagree. During his testimony, Dr. Young only briefly


9
     Notably, the City’s expert, Dr. Young, acknowledged during his testimony that the
DSM-5-TR is the most recent version of the DSM.

                                           19
referenced the term “lifetime PTSD” as used in the DSM-5-TR. He testified that he had

“heard” the phrase “in a sense that if you’re looking at . . . lifetime prevalence of PTSD or

if someone has ever met criteria for PTSD over the course of their lifetime, in that kind of

discussion context, but not as a diagnosis.” Considering the facts in the light most

favorable to the findings, the compensation judge’s failure to reference this specific portion

of Dr. Young’s testimony did not result in factual findings that are manifestly contrary to

the evidence. Moreover, given Dr. Young’s testimony, the WCCA’s finding that Dr.

Young offered no competing interpretation of the new text is supported by the record.

       To be clear, we do not endorse any interpretation of the DSM here. Our decision is

based on the application of our standard of review. The standard of review does not allow

us to substitute our judgment for the judgment of the compensation judge as to “which of

the professional diagnoses [was] more credible and persuasive.” Tea, 5 N.W.3d at 120

(citation omitted) (internal quotation marks omitted).

       Applying our standard of review, we discern no error in the WCCA’s decision to

affirm the compensation judge’s factual finding that Peterson has a current PTSD diagnosis

because the WCCA’s decision is not manifestly contrary to the evidence. Furthermore,

because Peterson has a present diagnosis of PTSD under the most recent version of the

DSM, the WCCA did not err in concluding that Peterson is entitled to workers’

compensation benefits.

                                             II.

       The City argues that the WCCA erred when it directed the compensation judge to

make additional findings regarding Peterson’s claim that he was entitled to workers’


                                             20
compensation benefits for OSTD as a consequential injury of PTSD. Further, the City

contends that the WCCA erred by addressing this claim after concluding that Peterson was

entitled to workers’ compensation benefits for a present diagnosis of PTSD because the

issue was moot. Peterson concedes that resolution of this issue may be unnecessary. But

he requests a decision from this court because the issue of whether OSTD is a compensable

mental impairment “has been percolating in the lower courts” and this court’s guidance is

needed.

      We agree with the City that the WCCA erred when it addressed the issue because

the issue was moot. An issue is moot if “a decision on the merits is no longer necessary or

an award of effective relief is no longer possible.” Dean v. City of Winona, 
868 N.W.2d 1, 5
 (Minn. 2015). The WCCA’s determination that Peterson is entitled to compensation

benefits for a present diagnosis of PTSD rendered a further decision regarding the merits

of Peterson’s OSTD consequential injury claim unnecessary.

      We reach this conclusion based on the record. Peterson’s initial claim petition

alleged that he had compensable PTSD. After Dr. Aleknavicius prepared her evaluation,

which stated that Peterson’s diagnosis was “OSTD (subthreshold PTSD),” Peterson

amended his claim petition, adding a second claim for a consequential mental injury of

OSTD. But at the hearing before the compensation judge, Dr. Aleknavicius modified the

earlier opinion that she had provided in her evaluation. She testified that, based on the

most recent edition of the DSM, Peterson has a present diagnosis of PTSD.              Dr.

Aleknavicius explained that, although she had previously diagnosed OSTD, Peterson’s

OSTD diagnosis was “subthreshold PTSD.” In other words, she diagnosed OSTD because


                                            21
Peterson’s PTSD symptoms had decreased when she met with him for the evaluation. The

City’s expert, Dr. Young, did not disagree with Dr. Aleknavicius’s characterization of

OSTD as a milder form of PTSD, noting that such disorders fall on a “spectrum.”10

Following the hearing, the compensation judge found Dr. Aleknavicius’s testimony to be

credible and persuasive.      The compensation judge concluded that Peterson has

compensable PTSD, and the WCCA affirmed the compensation judge’s findings.

Peterson, 
2024 WL 3363123
, at *15. Given Dr. Aleknavicius’s opinion that Peterson’s

OSTD diagnosis was “subthreshold PTSD” and the WCCA’s decision that Peterson was

entitled to compensation benefits for a present diagnosis of PTSD, a decision as to whether

Peterson’s OSTD diagnosis was a compensable mental impairment was no longer

necessary.11 Thus, the issue was moot.12

       Because the WCCA erred in addressing the question of whether Peterson was

entitled to workers’ compensation benefits for OSTD as a consequential mental injury, we


10
       As noted, however, Dr. Young disagreed with Dr. Aleknavicius’s opinion that
Peterson has a mental health disorder.
11
        We may avoid the mootness doctrine and exercise our discretion to consider the
merits of an issue if the issue is “ ‘functionally justiciable’ and presents an important
question of ‘statewide significance that should be decided immediately.’ ” Dean,
868 N.W.2d at 6
 (quoting State v. Rud, 
359 N.W.2d 573, 576
 (Minn. 1984)); see also
Winkowski v. Winkowski, 
989 N.W.2d 302
, 309 (Minn. 2023). An issue is functionally
justiciable if the record includes “the raw material . . . traditionally associated with
effective judicial decision-making”—namely, “effective presentation of both sides of the
issues raised.” Rud, 
359 N.W.2d at 576
. We decline to exercise our discretion to consider
the merits of the issue here.
12
       In its challenges to the WCCA’s referral order and holding regarding the
compensability of OSTD, the City raised multiple additional arguments that we do not
reach given our decision to reverse the WCCA’s decision on the ground of mootness.

                                            22
reverse the WCCA’s decision as to this issue. Additionally, we reverse the WCCA’s

holding that OSTD is a compensable consequential injury of PTSD.

                                            III.

       Finally, the City argues that the WCCA erred in upholding the compensation judge’s

award of a penalty against the City for frivolously denying primary liability in response to

Peterson’s claim for workers’ compensation benefits.           Peterson responds that the

compensation judge’s decision to award a penalty was an appropriate exercise of

discretion.

       As noted, when a police officer experiences PTSD and has not been previously

diagnosed with this condition, there is a presumption that it is an occupational disease “due

to the nature of employment.” 
Minn. Stat. § 176.011
, subd. 15(e). The officer’s employer

or insurer can rebut this presumption, but the employer or insurer “faces a higher burden

than in a case in which no presumption applies.” Juntunen v. Carlton County, 
982 N.W.2d 729
, 741 (Minn. 2022). The presumption can be rebutted only by “substantial factors.”

Minn. Stat. § 176.011
, subd. 15(e).     “If rebutted . . . , the presumption disappear[s].”

Juntunen, 982 N.W.2d at 741 (alteration in original) (citation omitted) (internal quotation

marks omitted). An employer or insurer that rebuts the presumption with substantial

factors and denies liability must communicate known substantial factors to the employee

at the time of denial of liability. 
Minn. Stat. § 176.011
, subd. 15(e). Denial of a claim

must be served on the employee within 14 days after the employer receives notice of or

knows of an alleged compensable injury. 
Minn. Stat. § 176.221
, subd. 1 (2024).




                                             23
       If an employer or insurer denies an employee’s workers’ compensation claim

without a “good faith investigation of the facts” or if the basis for denial “is clearly contrary

to fact or law,” it is considered a “frivolous[]” denial. 
Minn. Stat. § 176.225
, subd. 1

(2024).   When an employer or insurer frivolously denies an employee’s claim, the

employee is entitled to a penalty award “of up to 30 percent of th[e] total amount” of the

compensation award. 
Id.

       Here, the compensation judge concluded that the presumption of compensability

under section 176.011, subdivision 15(e), applied to Peterson, and the City failed to rebut

the presumption. The compensation judge further concluded that the denial was frivolous

because the City did not perform any investigation into Peterson’s claim before denying it,

and because the City’s “primary denial of liability inaccurately stated that the employee

had a ‘history of personal mental health conditions caused by personal emotional stressors

unrelated to employment.’ ” The compensation judge therefore decided that Peterson was

entitled to a penalty award under section 176.225, subdivision 1, in the amount of

30 percent of the total compensation award.

       The WCCA affirmed the compensation judge’s award of a penalty. Peterson,

2024 WL 3363123
, at *18. It determined that Peterson established that he was entitled to

the presumption that his PTSD diagnosis was work related. 
Id.
 The WCCA observed that

the City denied that the presumption applied, claiming that Peterson had a history of

personal mental health conditions unrelated to his employment as a police officer and that

these mental health conditions were being further investigated. 
Id.
 But the WCCA noted

that the record contradicts the City’s assertions. 
Id.
 The record shows that Peterson


                                               24
underwent two separate mental health examinations at the outset of his work for the City,

and both examinations concluded that Peterson did not have pre-existing mental health

issues. 
Id.
 Based on these findings, the WCCA concluded that the City’s denial of primary

liability was frivolous and the compensation judge’s award of a penalty was a proper

exercise of discretion. 
Id.

       We will overturn the WCCA’s findings “only if, viewing the facts in the light most

favorable to the findings, it appears that the findings are manifestly contrary to the evidence

or that it is clear reasonable minds would adopt a contrary conclusion.” Juntunen,

982 N.W.2d at 742 (citation omitted) (internal quotation marks omitted). Here, the

WCCA’s findings are not manifestly contrary to the evidence. Moreover, those findings

support the compensation judge’s decision to award a penalty.

       The City contends that it is unfair to require employers to rebut the presumption

within the statutory period of just 14 days. But as we have previously observed, we are

bound to follow the clear mandate of the statute, which serves a competing legislative

purpose. See Juntunen, 982 N.W.2d at 743 (“The Legislature determined that employees

suffering from PTSD need timely access to medical care, and the PTSD presumption puts

the onus on employers to quickly resolve such claims.”); Chrz, 986 N.W.2d at 487 (stating

that “we ‘must read this state’s laws as they are, not as some argue they should be’ ”

(quoting State v. Carson, 
902 N.W.2d 441, 446
 (Minn. 2017))); see also 
Minn. Stat. §§ 176.011
, subd. 15(e), 176.221.

       The facts in the record support the WCCA’s decision to affirm the compensation

judge’s award of a 30 percent penalty against the City for its frivolous denial of primary


                                              25
liability. Thus, we conclude that the WCCA did not err in affirming the award of the

penalty.

                                     CONCLUSION

       For the foregoing reasons, we affirm the decision of the Workers’ Compensation

Court of Appeals in part, and we reverse in part.

       Affirmed in part and reversed in part.




                                            26
                       CONCURRENCE&DISSENT

MOORE, III, Justice (concurring in part and dissenting in part).

       I write separately because I believe that the Workers’ Compensation Court of

Appeals (WCCA) committed an error of law in affirming the factual finding that Lucas

Peterson has a current diagnosis of post-traumatic stress disorder (PTSD) under the most

recent version of the Diagnostic and Statistical Manual of Mental Disorders, Textual

Revision (5th ed. 2022) (DSM-5-TR), based on a diagnosis of “lifetime” PTSD. The

WCCA’s acceptance of the compensation judge’s finding that Peterson met criteria for a

current PTSD diagnosis based on the new “lifetime” PTSD text referenced in the 2022

textual revision of the DSM-5-TR, notwithstanding the fact Peterson no longer met the

criteria for a current diagnosis of PTSD, is contrary to our opinion in Chrz v. Mower

County, 
986 N.W.2d 481
, 486 (2023). The WCCA’s finding that the respondent’s expert,

Dr. Young, “offered no interpretation of the new text” in the DSM-5-TR is also manifestly

contrary to the evidence. While I acknowledge that the court resolves this case without

adopting a definitive construction of the DSM-5-TR, I remain concerned that the majority

opinion may be construed as implicitly endorsing an expansive interpretation—one under

which an employee’s eligibility for workers’ compensation benefits based on a diagnosis

of PTSD could extend beyond the period in which the employee presently meets the

diagnostic criteria.   Such a construction would allow a PTSD diagnosis to persist

indefinitely for benefit purposes, a result this court rejected in Chrz. 
Id. at 486
. For these




                                           C/D-1
reasons, I respectfully dissent from parts I and III of the court’s opinion, and would reverse

the opinion of the WCCA on all questions presented.1

       In 2013, the Legislature amended the Minnesota Workers’ Compensation Act to

allow injured workers to recover workers’ compensation benefits for a diagnosis of PTSD

from a licensed psychiatrist or psychologist that arises out of and in the course of

employment. See 
Minn. Stat. § 176.011
, subds. 15(d), 16 (2024). The Legislature defined

PTSD as the “condition as described in the most recently published edition of the

Diagnostic and Statistical Manual of Mental Disorders by the American Psychiatric

Association.” 
Id.,
 subd. 15(d). At the time of our first case interpreting the 2013 workers’

compensation PTSD amendments, Smith v. Carver County, 
931 N.W.2d 390
 (Minn. 2019),

that version was “commonly known as the DSM-5.” 
Id.
 at 392 (citing Am. Psychiatric

Ass’n, Diagnostic and Statistical Manual of Mental Disorders (5th ed. 2013)). We

reasoned in Smith that the role of the fact-finder in cases involving workers’ compensation

PTSD claims is to review competing expert evaluations and determine which was more

persuasive based on the application of PTSD from the latest edition of the DSM. 
Id. at 398
.

And in Chrz we relied on Smith to reiterate that for an employee to recover workers’

compensation benefits for PTSD under the 2013 statutory amendments, the employee



1
       I concur with the opinion of the court as to part II because I agree that, in light of
the court’s resolution of the issues in part I, the WCCA should not have reached whether
Peterson was entitled to workers’ compensation benefits for other specified trauma and
stressor-related disorder (OSTD) as a consequential injury. But I disagree with the
majority’s holding regarding Peterson’s eligibility for continuing PTSD benefits, and
would also reverse the compensation judge’s finding that the City’s denial of liability was
frivolous. I thus dissent from parts I and III of the court’s opinion.

                                           C/D-2
“must prove that (1) a psychiatrist or psychologist has diagnosed the employee with PTSD,

and (2) the professional based the employee’s diagnosis on the latest version of the DSM.”

Chrz, 986 N.W.2d at 485 (citing Smith, 
931 N.W.2d at 396
).

       This case involves the application of a new version of the DSM to the PTSD

diagnosis—the DSM-5-TR, published in 2022. Am. Psychiatric Ass’n, Diagnostic and

Statistical Manual of Mental Disorders, Text Revision (5th ed. 2022). The compensation

judge concluded that, despite Peterson’s symptoms not meeting the DSM-5 criteria for

PTSD, that he still has PTSD based on meeting the criteria for a “lifetime diagnosis” of

PTSD under the DSM-5-TR. The issue before us is whether this conclusion was clearly

unreasonable, and therefore whether the WCCA’s affirmance of that finding was

manifestly contrary to the evidence. I believe that it was.

       In May 2022, Dr. Aleknavicius evaluated Peterson and reviewed his medical status

from the prior year. That review included Dr. Cronin’s June 2021 diagnosis of PTSD. Dr.

Aleknavicius concluded that Peterson had met all PTSD diagnostic criteria from around

March through June 2021, though treatment had improved some symptoms. But by the

time of her May 2022 evaluation, Peterson’s symptoms had shifted, and Dr. Aleknavicius

found that he no longer met Criteria F and G for a PTSD diagnosis.2 Dr. Aleknavicius

instead diagnosed him with other specified trauma and stressor-related disorder (OSTD),

cautioning that Peterson remained at significant risk for future PTSD episodes. In a later


2
       Criterion F applies when the duration of the symptoms in Criteria B, C, D, and E
last more than one month. Am. Psychiatric Ass’n, Diagnostic and Statistical Manual of
Mental Disorders, Text Revision 307 (5th ed. 2022). Criterion G applies when the
symptoms create distress or functional impairment. 
Id.

                                           C/D-3
certification prepared in October 2022, Dr. Aleknavicius confirmed these findings and

supported Peterson’s workers’ compensation claim because he had a different condition,

OSTD, rendering him unfit to perform the duties of a police officer.

       At the hearing before the compensation judge in April 2023, while testifying, Dr.

Aleknavicius opined for the first time that Peterson met all PTSD criteria under the

March 2022 DSM-5-TR update. She testified that PTSD remains a valid, continuing

diagnosis once the relevant symptom clusters have been simultaneously present for at least

one month. She explained that PTSD is a lifetime condition once the four diagnostic

criteria are met. In other words, Dr. Aleknavicius testified that Peterson’s PTSD diagnosis

is perpetual.

       In contrast, Dr. Young conducted an independent medical examination in

March 2022, and concluded that Peterson had no diagnosable mental health condition and

found ongoing treatment unnecessary. During testimony at the hearing, Dr. Young

contested the applicability and significance of the DSM-5-TR update referenced by Dr.

Aleknavicius. Dr. Young asserted that the DSM-5-TR was merely an administrative

revision, not a substantive clinical update, noting that the diagnostic criteria for PTSD were

unchanged from the DSM-5. He rejected the concept of “lifetime PTSD” as a recognized

diagnosis within the mental health profession, asserting instead that PTSD must be

continually reassessed based on a patient’s current symptom presentation, and that the

“lifetime” language refers to PTSD’s prevalence as a disorder.

       Despite Dr. Young’s opinions objecting to the interpretations of the DSM-5-TR,

after weighing all expert testimony, the compensation judge credited Dr. Aleknavicius’s


                                           C/D-4
explanations and an earlier evaluation from 2021, finding them consistent with the record

and more persuasive than Dr. Young’s contrary opinions. Consequently, the compensation

judge concluded that Peterson had established a compensable PTSD injury.

       The WCCA affirmed the compensation judge’s decision in all respects. Peterson v.

City of Minneapolis, No. WC23-6527, 
2024 WL 3363123
, at *19 (Minn. WCCA June 28,

2024). It recognized that the compensation judge reasonably credited Dr. Aleknavicius,

who relied on the DSM-5-TR, and her explanation of “lifetime” PTSD once the core

diagnostic criteria have been met. 
Id.
 at *14–15. As explained by the WCCA, Dr. Young

based his analysis on the earlier DSM-5 and contested the possibility of a lifetime diagnosis

without offering a different interpretation of the DSM-5-TR.         
Id. at *15
.    Because

Minnesota law directs the fact-finder to apply the most recent DSM edition and because

substantial evidence supported Dr. Aleknavicius’s testimony, the WCCA concluded the

compensation judge did not err in finding Dr. Aleknavicius’s testimony more persuasive

than that of Dr. Young. 
Id.

       Our review of factual findings in workers’ compensation cases is limited. Tea v.

Ramsey Cnty., 5 N.W.3d 114, 119 (Minn. 2024). Because the WCCA affirmed the

compensation judge’s factual findings, we “must uphold those findings unless they are

‘manifestly contrary to the evidence.’ ” 
Id.
 (quoting Schmidt v. Wal-Mart Stores, Inc.,

988 N.W.2d 124
, 129 (Minn. 2023)). To be manifestly contrary to the evidence, the

evidence must “clearly require[] reasonable minds to adopt a contrary conclusion.”

Lagasse v. Horton, 982 N.W.3d 189, 202 (Minn. 2022).




                                           C/D-5
       “When medical professionals provide competing diagnoses, the compensation

judge must determine ‘whether the expert diagnoses have adequate foundation and, if both

have adequate foundation, decide which of the professional diagnoses is more credible and

persuasive.’ ” Tea, 5 N.W.3d at 120 (quoting Juntunen v. Carlton Cnty., 
982 N.W.2d 729
,

743 n.10 (Minn. 2022)). The compensation judge, however, may determine that a PTSD

diagnosis is “inconsistent with the DSM” based on “evidence offered by another medical

professional.” 
Id. at 122
. But that determination is “not based upon the judge’s own

application of the DSM criteria to the employee’s symptoms.” 
Id.
 Here, the compensation

judge found Dr. Aleknavicius’s lifetime PTSD diagnosis more credible and persuasive.

       But I have serious doubts that the evidence supports Dr. Aleknavicius’s claims about

“lifetime PTSD.” The disputed portion of the DSM-5-TR states:

       The diagnosis of PTSD requires that the duration of the symptoms in Criteria
       B, C, D, and E be more than 1 month (Criterion F).

       For a current diagnosis of PTSD, Criteria B, C, D, and E must all be met for
       more than 1 month, for at least the past month.

       For a lifetime diagnosis of PTSD, there must be a period of time lasting more
       than 1 month during which Criteria B, C, D, and E have all been met for the
       same 1-month period of time.

Am. Psychiatric Ass’n, Diagnostic and Statistical Manual of Mental Disorders, Text

Revision 307–08 (5th ed. 2022) (emphasis added). The criteria of the last two sentences

seem to operate identically. But it defies logic that the criteria for a present PTSD diagnosis

would be identical to the criteria necessary to sustain a “lifetime” diagnosis. Put another

way, under Dr. Aleknavicius’s reading of this language, any time a person is diagnosed

with PTSD, they have PTSD for a lifetime. But the experts here agreed that the DSM-5-TR


                                            C/D-6
did not change the diagnostic criteria for PTSD.3 Dr. Young’s main objection to Dr.

Aleknavicius’s testimony was that the diagnostic criteria for PTSD in the DSM-5-TR are

no different from the criteria in the DSM-5. Rather, Dr. Young testified that the “lifetime”

language refers to “lifetime prevalence of PTSD or if someone has ever met criteria for

PTSD over the course of their lifetime . . . but not as a diagnosis.”

       In Chrz, we confirmed that Minnesota’s workers’ compensation laws treat PTSD as

a condition that can, and does, resolve over time. 986 N.W.2d at 486. There we held that

a deputy sheriff who had been diagnosed with PTSD in 2019 was no longer entitled to

benefits once he no longer had a PTSD diagnosis in early 2021. Id. at 487. We explained

that the statute “plainly decide[s] that an employee is only eligible for workers’

compensation benefits so long as they meet the precise definition of PTSD,” warning that

extending benefits after the diagnosis resolves “would allow an employee’s diagnosis of

PTSD to remain effectively perpetual.” Id. at 486. Chrz therefore suggests that under the

DSM-5—and thus under the DSM-5-TR, because the diagnostic criteria for PTSD are

identical—PTSD cannot be considered a permanent (or lifetime) diagnosis. This is because

once the clinical criteria are no longer met, the law regards the worker as having recovered,



3
        The only modification to the PTSD diagnostic criteria in the DSM-5-TR applies
exclusively to children. See Am. Psychiatric Ass’n, Rationale for Change: Posttraumatic
Stress Disorder (2022), https://www.psychiatry.org/getmedia/eacace92-3964-4350-a0bd-
e42fc03e806a/APA-DSM5TR-PTSD.pdf [opinion attachment]. And no changes were
made to the PTSD diagnostic criteria for adults in the DSM-5-TR. See U.S. Dep’t of
Veterans        Aff.,       PTSD:         National        Center         for        PTSD,
https://www.ptsd.va.gov/professional/treat/essentials/dsm5_ptsd.asp (last visited June 30,
2025) [opinion attachment] (“With no changes to the diagnostic criteria in DSM-5-
TR . . . .”).

                                           C/D-7
terminating the “occupational disease” and any consequent benefits payable because of

that occupational disease. Id.

       Because the WCCA affirmed the factual finding of Peterson’s present diagnosis of

PTSD despite his symptoms not meeting the requirements of the DSM-5, the WCCA

necessarily concluded that new language in the DSM-5-TR permits a psychiatrist to make

an active diagnosis of PTSD in circumstances under which the DSM-5 did not. I believe

that conclusion was a legal error, and I therefore would reverse the decision of the WCCA

on that basis.

       Accordingly, I respectfully dissent as to parts I and III of the court’s opinion.



THISSEN, Justice (concurring in part and dissenting in part).

       I join the opinion of Justice Moore concurring in part and dissenting in part.




                                           C/D-8
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Reference

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Published