All BD, cannabis involvement and psychpathology measures were collected using the semi-structured DIGS 4.0. Best estimate diagnosis of DSM-IV (American Psychiatric Association, 1994) BD and BD spectrum disorders were used. 89.8% of the 471 cases, were diagnosed with Bipolar I, 6.7% with Schizoaffective, Bipolar, and the remainder with Bipolar II (with recurrent depression) or Bipolar NOS. While no adjustments were made for confidence associated with diagnosis, 80% of the subjects were diagnosed with definite diagnostic confidence with the remainder being diagnosed with a high level of confidence (only missing supporting observations). Diagnoses for comorbid DSM-IV psychiatric and substance use disorders were also extracted from the best estimate diagnosis section. Clinical features of BD were rated by a clinician, based on responses to a variety of questions in the DIGS as well as interviewer narratives. For instance, BD-related disability was rated by a clinician as follows: 0=never ill, 1=no loss of employment or marital status, 2= loss of status but not disabled, 3=disabled but lives independently, 4=disabled and not living independently. This rating was based on multiple interview items rating general
