Cannabis abuse in patients with schizophrenia: pattern and effects on symptomatology

To determine the relationship between cannabis abuse and its impact on the short-term outcome and severity of illness.

Case control study.

This study was conducted at P.G.M.I. Lady Reading Hospital, Peshawar from January to October 2004.

ICD-10 criteria were used for diagnosis of schizophrenia. Severity and type of schizophrenic symptoms were assessed with the help of PANSS. Cases were identified as having problem with cannabis use with the help of section 12 of Schedule for Clinical Assessment in Neuropsychiatry (SCAN) W.H.O. 1994. Amount, duration and frequency of cannabis use was also noted.

Patients with cannabis use were younger had shorter duration of illness and earlier age at onset of illness. They exhibited more positive symptoms. A total of 20% cases met ICD-10 criteria of harmful use of cannabinoid, 76% met ICD-10 criteria of cannabinoid dependence syndrome.

Schizophrenic patients with comorbid cannabis abuse exhibited more positive symptoms and violent behavior, and may be more likely to lead to dependence in persons with schizophrenia. This has implication for service development to meet the perceived needs of this group.