The DSM is a resource mental health professionals can turn to for standardized diagnostic criteria for mental health conditions, including depression.

The reason why mental health professionals can use the DSM-IV for diagnosis is because the DSM derives its code numbers from the ICD. Currently, the DSM-IV code numbers reflect the ICD-9-CM codes.

The Diagnostic and Statistical Manual of Mental Disorders (DSM) is the primary tool that mental health professionals in the United States use to diagnose anxiety disorders.

However, the DSM-5 codes will have to reflect those from the ICD-10-CM because use of the ICD-10-CM becomes mandatory by all health professionals in October 2013.