Depression: relationship to somatization and chronic medical illness.

Although depression has been found to be the most common medical or psychiatric diagnosis among patients seen in primary care settings, the disorder is often missed and/or treated inappropriately. Problems in differential diagnosis, particularly among patients presenting primarily with somatic complaints, are reviewed. A study is described in which patients referred to a psychiatric consultation-liaison service were categorized as somatizing or nonsomatizing and given DSM-III diagnoses. Somatoform disorders occurred in only 33% of somatizing patients; the predominant diagnosis in this group was major depression. Implications of these findings for the recognition and treatment of depression, especially that associated with physical symptoms or disease, are discussed.