A4: Classification of disorders

This chapter provides a brief overview of the mental disorders most commonly seen among clients of AOD treatment settings. Not all AOD workers are able to formally diagnose the presence or absence of mental disorders. Diagnoses of mental disorders should only be made by suitably qualified and trained health professionals (e.g., registered or clinical psychologists, and psychiatrists). It would be unethical for non-trained workers to use diagnostic labels in clinical notes, or to inform the client that they have a diagnosis, unless they have received written confirmation from a suitably qualified professional.

It is nonetheless useful 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 (discussed in Chapter B2), and to inform treatment planning. Many more people will present with symptoms than will meet criteria for a diagnosis of a disorder; however, these symptoms are distressing and need to be managed nonetheless. It is hoped that the descriptions provided here will increase AOD workers’ knowledge and awareness of different signs (i.e., what is objectively visible about the client, such as sweating) and symptoms (i.e., what the client describes, such as sadness) of disorders. The case studies provided throughout these Guidelines also provide examples of how symptoms may present in clients with co-occurring mental disorders.

There are many kinds of mental disorders, with each disorder comprising a group of signs and symptoms. A certain number of criteria for a particular disorder need to be met within a certain timeframe for a person to be diagnosed as having that disorder. However, as described in Chapter A1, there are many people who present to AOD treatment who display symptoms of disorders, while not meeting criteria for a diagnosis of a disorder. For example, a person may present with depressed mood or anxiety symptoms, without having a diagnosable depressive or anxiety disorder. Although these people may not meet full diagnostic criteria according to the classification systems, their symptoms may nonetheless impact significantly on their functioning and treatment outcomes [26, 27, 152]. As such, rather than viewing mental health as merely the presence or absence of disorder, it may be more useful to consider mental health conditions as a continuum, ranging from mild symptoms to severe disorders (Figure 8).