Khat use among Somali mental health service users in South London

Khat use has been suggested to be associated with psychosis, but its prevalence and associations among mental health service users have not been described in either traditional use countries or countries with immigrant populations from traditional use countries. We aimed to investigate the clinical and demographic associations of khat use in a sample of Somali users of mental health service users in South London. We used an electronic case register of 150,000 mental health patients to investigate the associations of khat use among all 240 Somali patients in the database. We used logistic regression to generate adjusted estimates for a range of exposure variables and used multiple imputation as a principled approach to missing data. Khat use or non-use was recorded for 172 patients (72% of the total), of whom 80 (47%) were current users. Khat use was very strongly associated with ICD-10 primary diagnosis of schizophrenia, psychosis or drug and alcohol disorder (compared to ICD-10 F43 stress-related disorders and other non-psychotic disorders), male gender, harmful or dependent use of alcohol, and detention under the Mental Health Act. Recording and monitoring of khat use need to be more consistent in clinical settings, and further studies are required to investigate the much higher rates of use among those with psychotic disorders compared to non-psychotic disorders.