Cannabis use in psychotic patients.

OBJECTIVE

The purpose of this study was to examine the level of cannabis use in psychotic patients admitted to two acute admission wards in New Zealand. Symptomatology was investigated using the Brief Psychiatric Rating Scale (BPRS).

METHOD

During a 1 -month period, all acute admissions to Tokanui Hospital with psychosis were interviewed and symptoms rated on the BPRS (n = 35). Cannabis use was recorded with a questionnaire and urine test. Those positive for cannabis were compared to those negative.

RESULTS

Thirty patients (86%) had tried cannabis at least once and 11 (31%) were positive on urine screen. Those with positive urine tests were significantly more likely to use cannabis most days (p < 0.001). This positive urine test group was less likely to be thought disordered, suspicious or deluded (as measured by the BPRS).

CONCLUSIONS

Cannabis use was widespread in this sample of patients with psychosis and may affect their symptomatology. Larger studies are needed to examine these associations in more detail.