Dual diagnosis refers to the co-occurrence of a mental health disorder and a substance use disorder in an individual. This means that a person is struggling with both a mental health condition (such as depression, anxiety, bipolar disorder, or schizophrenia) and a substance abuse problem (such as alcohol, drugs, or both). Dual diagnosis requires integrated treatment that addresses both the mental health disorder and the substance use disorder concurrently. This can involve a combination of medication, therapy, support groups, and other services to help the individual manage their symptoms and achieve recovery.