Testing for illicit drug use in mental health services

Illicit drug use is the practice of consuming a legally restricted substance in a manner contrary to the moral or traditional practices of a particular culture. In 2005/2006, over 10% of adults between 16 and 59 years of age had used illicit drugs in the previous year (Home Office 2006). The use of ‘Class A drugs’ (usually heroin or cocaine) was over 3%, mainly because of the rise in cocaine use. In younger adults aged between 16 and 24, illicit drug use was over 25% in the previous year; 17% of children aged 11–15 reported taking drugs in the previous year and 9% in the past month (Home Office 2006). The prevalence in mental health services is much higher: 25% of adult and up to 50% of adolescent in-patients in psychiatric units have an illicit drug use disorder (Crome 2006). Testing for illicit drug use involves the analysis of biological material to detect drugs or their metabolites in the body. In mental health services it is used both to confirm diagnosis and manage care. Courts and doctors are often asked to perform and interpret the results of drug and alcohol tests for these civil proceedings. Quality control and types of drug analysis