Problematic cannabis use amongst those with severe mental health problems in an inner city area of the UK

The prevalence and nature of cannabis use amongst those with severe mental health problems in community-based services in an inner city area of the UK was assessed. A questionnaire completed by keyworkers of clients engaged with statutory services assessed mental health problems, patterns of substance use, and perceived reasons for substance use. One hundred fifty-nine keyworkers gave information on 1369 clients with severe mental health problems. Three hundred twenty-four of these clients were identified as also using substances problematically. Forty-three percent (139/324) of these clients were misusing cannabis. Within mental health services, cannabis, second to alcohol, was the substance most commonly used problematically. Problematic cannabis use was most frequently associated with males and a diagnosis of schizophrenia, schizotypal or delusional disorders. The median age was 30 years. Pleasure enhancement and coping reasons were most commonly cited by keyworkers for their clients' substance use. Problematic cannabis use was common. Due to the fairly unique profile of cannabis and the emphasis/focus of treatment services, it is possible that cannabis use may be too heavily emphasised or too easily ignored by health professionals.