As many as 80% of alcoholics experience depressive symptoms, including 30% who fulfil criteria for a major depressive disorder (Raimo & Schuckit, 1998). A lifetime history of depressive disorder has been found in 48% of opiate addicts (Rounsaville et al, 2001). Thus, it is clear that substance misuse and depressive symptoms often occur together, but what is less clear is their true relationship. Box 14.1 shows three frequently asked questions concerning it.

The combination of depressive symptoms and substance misuse presents important management issues, both at the level of the individual patient and regarding service provision. In individual patients it is often difficult to disentangle all threads of the presentation. An unusual mental state may be due to intoxication, and substance misuse may be hidden. A frequent management dilemma is the intoxicated patient in the middle of the night, who has self-harmed, or is threatening to do so.

Although depressive symptoms and substance misuse commonly occur together, services for their joint management do so less frequently; one editorial talks of the ‘medical model of psychiatric services […] contrasting sharply with the psychosocial orientation of substance misuse services’ (Weaver et al, 1999).