The co-occurrence of different disorders, whereby individuals who have one mental disorder also suffer from another, is identified by the DSM as 'dual diagnosis' or 'co-occurring disorders'
Explanation:
The 'Diagnostic and Statistical Manual of Mental Disorders' (DSM) describes the existence of two different disorders in an individual as 'co-occurring'. These can be two mental disorders happening in the same person or, <em>more commonly</em>, a combination of a mental disorder and a subtance use disorder, such as <em>alcohol or drugs</em>. Individuals who have a combination of disorders face more challenges and generally need longer treatments than those who only have one disorder.