Insanity plea: predicting not guilty by reason of insanity adjudications.

Using 35 variables and discriminant analysis procedures, it was found that, of 133 male defendants entering the insanity plea in Colorado, 87 percent were classified correctly into the disposition groups "adjudicated insane" and "convicted." Most positively related to an insanity adjudication were a psychiatric evaluation of insanity and a diagnosis of schizophrenia. Negatively related to the insanity verdict were diagnoses of substance use and personality disorders.