Does a court have a sua sponte duty to instruct on mental impairment as a defense?

A trial court has no sua sponte duty to instruct on mental impairment as a defense; however, the court must give the instruction upon request if it is supported by the evidence. (People v. Saille (1991) 54 Cal.3d 1103, 1119 ["Such instructions relate particular facts to a legal issue in the case or 'pinpoint' the crux of a defendant's case . . . . [Citation.] They are required to be given upon request when there is evidence supportive of the theory, but they are not required to be given sua sponte"].)