Joel Paris’s scientific contributions

This review examines whether the diagnosis of dissociative identity disorder (DID) could be used to support a defence of ‘not guilty by reason of insanity’ (NGRI, or the insanity defence). The problem is that DID has doubtful validity and can easily be malingered. However, the diagnosis is listed in standard psychiatric manuals. If accepted as valid, DID would have problematic forensic implications. LEARNING OBJECTIVES After reading this article you will be able to: • understand the history of the DID diagnosis • evaluate the validity of the DID diagnosis • appreciate, from case law, use of DID in support of an insanity defence. DECLARATION OF INTEREST None.

Borderline personality disorder (BPD) has a wide range of symptoms and clinical features that overlap with other diagnostic categories. Diagnosis is important because different disorders respond to different forms of treatment. Differential diagnosis is particularly relevant for distinguishing BPD from bipolar spectrum disorders, requiring a careful evaluation of affective instability and hypomania. BPD may also be confused with major depression, schizophrenia, attention-deficit/hyperactivity disorder, and posttraumatic stress disorder.