Is evidence of mental disease, mental defect or mental disorder admissible in a criminal case?

^7. "Evidence of mental disease, mental defect, or mental disorder is admissible solely on the issue of whether or not the accused actually formed a required specific intent, premeditated, deliberated, or harbored malice aforethought, when a specific intent crime is charged." ( 28, subd. (a).) "[A]n expert may not offer an opinion regarding whether the defendant had the capacity to form the intent required for the crime, or whether the defendant actually did form the requisite intent." (People v. Smithey (1999) 20 Cal.4th 936, 960; 29 ["In the guilt phase of a criminal action, any expert testifying about a defendant's mental illness, mental disorder, or mental defect shall not testify as to whether the defendant had or did not have the required mental states"]; 28, subd. (a) ["Evidence of mental disease, mental defect, or mental disorder shall not be admitted to show or negate the capacity to form . . . intent"].)