Background: Improved management of mental illness and substance misuse comorbidity is a National Health Service priority, but little is known about its prevalence and current management.
Aims: To measure the prevalence of comorbidity among patients of community mental health teams (CMHTs) and substance misuse services, and to assess the potential for joint management.
Method: Cross-sectional prevalence survey in four urban UK centres.
Results: Of CMHT patients, 44% (95% CI 38.1-49.9) reported past-year problem drug use and/or harmful alcohol use; 75% (95% CI 68.2-80.2) of drug service and 85% of alcohol service patients (95% CI 74.2-93.1) had a past-year psychiatric disorder. Most comorbidity patients appear ineligible for cross-referral between services. Large proportions are not identified by services and receive no specialist intervention.
Conclusions: Comorbidity is highly prevalent in CMHT, drug and alcohol treatment populations, but may be difficult to manage by cross-referral psychiatric and substance misuse services as currently configured and resourced.