The American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) provides symptom criteria to aid in the diagnosis of mental health disorders.

What criteria are required to diagnose Major Depressive Disorder?

A. The client must have 5 or more symptoms for at least 2 weeks; this must be a change from previous mood; at least one of the symptoms is either (1) depressed mood or (2) loss of interest or pleasure.
B. The client must have 4 or more symptoms for at least 4 weeks; this must be a change from previous mood; at least one of the symptoms is either (1) depressed mood or (2) loss of interest or pleasure.
C. The client must have 5 or more symptoms for at least 4 weeks; this must be a change from previous mood; at least one of the symptoms is either (1) depressed mood or (2) loss of interest or pleasure.
D. The client must have 4 or more symptoms for at least 2 weeks; this must be a change from previous mood; at least one of the symptoms is either (1) depressed mood or (2) loss of interest or pleasure.