Correlations between cannabis-induced psychopathology and EEG before and after drug ingestion.

The study investigates EEG characteristics in relation to psychopathology. Tetrahydro-Cannabinol (THC) was taken orally by 12 volunteers. The EEG was recorded continuously, and THC-induced psychopathology was assessed by pre- and post-experiment questionnaires. Subjects had to signal THC experiences. EEG measurements (distribution means of frequency bands derived from EEG frequency analysis) before and after THC were correlated with THC induced psychopathology. High correlations were found before THC ingestion, and after THC during periods without experiences. Thus, the pre-drug EEG indicates predisposition to THC induced body image disturbances and euphoria, and the drug-influenced EEG in periods without experiences indicates the tendency to drug-induced experiences. The predicting EEG parameters were different for THC induced visual experiences and for body image disturbances.