Cannabis and neuroleptic agents in schizophrenia.

A description is given of 10 schizophrenic patients whose condition was acutely aggravated following cannabis use, despite verified adequate depot treatment with neuroleptics. It is concluded that cannabis use constitutes a risk factor for schizophrenic patients, and the hypothesis is suggested that there may exist a cannabis-neuroleptics antagonistic interaction. Recent research in cannabis pharmacokinetics is presented in support of this hypothesis.