Excluding personality disorders from the insanity defense--a follow-up study

Examining the effects of Oregon's statutory reform excluding personality disordered individuals from the insanity defense, we previously identified a study sample of insanity acquittees, each of whom was given a primary diagnosis of a personality disorder during subsequent evaluation at the state hospital. In the present study we explore the relationship between that diagnosis and the pretrial psychiatric diagnosis presented to the trial court. By reading the forensic mental health evaluations used at trial we found that 50 percent of our study sample of 34 personality disordered patients were diagnosed with psychotic disorders, affective disorders, retardation, and organic brain disorders. In addition to investigating the diagnosis offered as evidence at trial, we performed assessments of 38 mental health reports using published standards for forensic evaluation reports. We found compliance rates in the various categories ranged from 8 to 84 percent with a mean of 45 percent. We question the value of the mental health input to these trials, and believe that the data tend to validate past aspersions of forensic practice.