Affect processing and positive syndrome schizotypy in cannabis users

Psychiatry Res. 2008 Jan 15;157(1-3):279-82. doi: 10.1016/j.psychres.2007.02.010. Epub 2007 Sep 27.


While cannabis is associated with positive syndrome schizophrenia (SZ), it is unclear whether cannabinoids are also related to negative symptoms such as affective blunting. We examined whether cannabis use is associated with schizotypy and utilized event-related potentials (ERPs) to assess affect processing. Cannabis users demonstrated increased P300 amplitudes for unpleasant trait words, and demonstrated higher positive syndrome schizotypy which correlated with levels of cannabis use. The cannabis group also exhibited lower negative syndrome schizotypy. The lack of blunted responses during the affect ERP and decreased negative subscale schizotypy scores provide evidence that the endocannabinoid theory of schizophrenia may be primarily relevant in relation to positive syndrome SZ.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Affect*
  • Brain / physiopathology
  • Electroencephalography
  • Event-Related Potentials, P300 / physiology
  • Expressed Emotion
  • Female
  • Humans
  • Judgment
  • Male
  • Marijuana Abuse / epidemiology*
  • Marijuana Abuse / physiopathology*
  • Schizotypal Personality Disorder / diagnosis
  • Schizotypal Personality Disorder / epidemiology*
  • Schizotypal Personality Disorder / physiopathology*
  • Severity of Illness Index