Is anhedonia a good measure of depression?

The symptom of anhedonia, or loss of pleasure, is widely recognized to occur in depression. More recently it has been suggested that this symptom alone might be the basis for a diagnosis of depression in medically ill patients, and the Hospital Anxiety and Depression Scale (HAD) has been designed with this in mind. To test the hypothesis that this symptom might discriminate well between major depressive disorder and other mental disorders, this study measured the degree and incidence of anhedonia in 147 consecutive psychiatric outpatients with a variety of DSM-III-R diagnoses. Anhedonia was assessed using items from the HAD. The results showed that, although depressed patients scored highly for anhedonia, this symptom was present in the majority of patients with diagnoses other than major depressive illness. Thus this symptom alone was unable to clearly distinguish between mental disorders, and it may therefore be inappropriate to use anhedonia as the basis for a diagnostic measure.