Part A of the Guidelines aims to provide workers with background information about co-occurring AOD and mental health conditions. In this document, we use the term ‘mental disorder’ when referring to people with a diagnosable mental disorder as defined by the DSM, as well as ‘mental health condition’, when referring to both those who have a diagnosable disorder as well as those who display symptoms of disorders while not meeting criteria for a diagnosis of a disorder. Although there may be several reasons why two or more disorders may co-occur, it is most likely that the relationship between co-occurring conditions is one of mutual influence (see Chapter A1).
Mental disorders are common among clients of AOD services, in particular, anxiety, depression, PTSD, and personality disorders (see Chapter A2). In addition, there are many people who present to AOD treatment who display symptoms of disorders while not meeting criteria for a diagnosis of a disorder. While people who experience co-occurring conditions may have more complex profiles, they have been found to benefit as much from traditional AOD treatment methods as those without co-occurring mental health conditions.
When working with clients with co-occurring mental health conditions, it is recommended that AOD services and AOD workers consider the guiding principles described in Chapter A3. Although not all AOD workers are able to formally diagnose the presence or absence of mental disorders, it is important for all AOD workers to be aware of the characteristics of disorders so that they are able to describe and elicit information about mental health symptoms when undertaking screening and assessment, and to inform treatment planning (see Chapter A4).