Does the diminished capacity defense of diminished capacity apply to reduce murder to manslaughter?

[230 Cal.App.3d 792] Even though the defense of diminished capacity is no longer available to reduce murder to manslaughter, a defendant still has the right pursuant to Penal Code sections 28, subdivision (a) and 29 "to show that a mental disease, defect or disorder prevented him from actually forming any required mental state, including intent." (People v. Leever (1985) 173 Cal.App.3d 853, 865-866, 219 Cal.Rptr. 581.) Thus, a defendant can show the absence of malice--either express or implied--in this same manner.