Irritable mood in Italian patients with medical disease.

Irritability may be a mood state independent of other moods and anxiety disorders, even though it may be symptomatic of several psychiatric disorders, such as major depression. The aims of this exploratory study were to verify the presence of irritable mood in a group of medical outpatients with a variety of clinical conditions (functional gastrointestinal disorders, cardiovascular disorders, endocrine diseases and cancer) and to examine its relationship with major depression. A total of 609 consecutive outpatients recruited from different medical settings were assessed according to DSM-IV and Diagnostic Criteria for Psychosomatic Research using semistructured research interviews. Irritable mood was identified in 163 (27%) patients, while major depression was present in 113 (19%) patients. Even though there was a considerable overlap between the two diagnoses, 76 (67%) patients with major depression were not classified as irritable, and 126 (77%) patients with irritable mood did not satisfy the criteria for major depression. The findings suggest a high prevalence of irritability in the medically ill, which in most cases is independent of mood disorder. Further research may determine whether irritability, alone or in association with major depression, entails prognostic and clinical implications.