Which statement best describes dual diagnosis in practice?

• A. It involves two separate mental health disorders.
• B. It refers to substance use with a physical illness only.
• C. It involves co-occurring mental health and substance use disorders.
• D. It refers to a single mental health disorder.

Answer: (C)

Dual diagnosis means recognizing that many clients present with both a mental health disorder and a substance use disorder, and these conditions influence each other. In practice, this requires screening for both conditions, making accurate diagnoses for both, and developing an integrated treatment plan that addresses both simultaneously rather than treating them separately. The approach combines appropriate psychotherapy and, when indicated, medication management, along with supports that tackle social and functional factors to reduce symptoms and prevent relapse. This is different from simply having two mental health disorders with no substance involvement, or from substance use occurring with a physical illness, or from dealing with a single mental health disorder in isolation.