UPON DUE CONSIDERATION of this appeal from a judgment of the United States District Court for District of Vermont (William K. Sessions III, Judge ), it is hereby

ORDERED, ADJUDGED AND DECREED that this appeal is DISMISSED.

Defendant-appellant John Jay North (“North”) appeals his sentence entered in the United States District Court for the District of Vermont (Sessions, /.). North pleaded guilty to possessing a firearm after having been convicted of a misdemean- or crime of domestic violence in violation of 18 U.S.C. § 922(g)(9), and the district court sentenced him to 30 months imprisonment, to be followed by two years of supervised release. North moved for a downward departure under § 5K2.13 of the United States Sentencing Guidelines (“U.S.S.G.”), alleging that he had a diminished capacity because of his low IQ1 and attention deficit disorder.2

In denying North’s downward departure motion, the district court stated: It does *20seem to me that in this case there has been no showing, and indeed ... there cannot be any showing ... that the diminished capacity would have contributed to the commission of the offense. And that is required by 5K2.13. I also think that in light of the overall circumstances, even if that sentence of 5K2.13 was not in the guideline, that the diminished capacity with this particular offense is not ... justified----The court would have discretion if that language didn’t exist to depart, and I just don’t think a departure in this case is warranted by the facts.

On appeal, North argues that the district court failed to recognize its authority to depart on the basis of diminished capacity absent a causal nexus between the diminished capacity and the crime committed.3 A district court’s refusal to grant a downward departure is not appealable unless the court committed an error of law or misapprehended its power to depart. See United States v. Napoli, 179 F.3d 1, 18 (2d Cir. 1999); United States v. Fernandez, 127 F.3d 277, 282 (2d Cir. 1997). However, we have repeatedly held that a district court’s misunderstanding of its authority to depart is moot if the court determines that even if it did have authority to depart, such a departure would be unwarranted on the facts of the case. See United States v. Acevedo, 229 F.3d 350, 356 (2d Cir. 2000) (holding that this Court need not review the decision of district court that defendant’s charitable conduct was not a basis for a downward departure in light of the court’s “alternative holding” that, in any event, the act was not so exceptional as to warrant a departure on the facts); Napoli, 179 F.3d at 18 (holding that this Court “need not review the district court’s conclusion that it lacked authority to depart ... because here the district court expressly stated that even if it had authority, it would not exercise it as a matter of discretion”).

We, therefore, DISMISS this appeal.