How is persistent depressive disorder diagnosed?
If depressive symptoms are present, the doctor will perform a comprehensive medical history and physical examination. Although there are no laboratory tests designed to specifically diagnose depressive disorders, the doctor might use diagnostic tests to rule out physical illness as the cause of the depression.
If no physical illness is found, a referral may be made to a psychiatrist or psychologist – mental health professionals who are trained to diagnose and treat mental illnesses. Psychiatrists and psychologists utilize clinical interviewing and assessment tools to evaluate a person for a depressive disorder. The psychiatrist or psychologist will then base his or her diagnosis on the patient's report of the intensity and duration of symptoms – including any problems with daily functioning caused by the symptoms – as well as on observations of the patient's attitude and behavior.