What is the test for a diminished capacity defense in a sexual assault case?

Serna moved for reconsideration, orally and in writing, citing People v. Padilla (2002) 103 Cal.App.4th 675 (Padilla) and CALCRIM No. 627.⁵ She argued that evidence of her mental illness was relevant to show that her thought processes were encumbered or defective, tending to negate deliberation and premeditation. The trial court denied the motion in a second written order. The court characterized Serna's argument as a diminished capacity defense, which is prohibited under section 25. The court also concluded there was no nexus between Serna's symptoms and her commission of the offense, distinguishing her argument from the holdings set forth in Padilla, supra.