• The incidence and severity of somatic symptoms were determined in 132 patients with major depressive disorder and 80 normal controls. The role of somatic symptoms was analyzed in relation to the unipolar-bipolar division, Research Diagnostic Criteria (RDC) subtypes, hypersomnia, and appetite increase. The data suggest that (1) the rate and level of somatic symptoms increased with the severity of depression and age, (2) only appetite loss differentiated unipolar from bipolar patients, and (3) the classic somatic symptoms of depression were present in most RDC subtypes and not exclusively associated with the "endogenous" subtype. Hypersomnia or increased appetite identified two overlapping depressive subgroups; patients in both groups were young and characterized by high interpersonal sensitivity. Hypersomniac depressed patients were less anxious and agitated; patients with increased appetite were more hostile and showed a greater decrease in libido than age-matched and sexmatched patients with neither symptom.
Casper RC, Redmond DE, Katz MM, Schaffer CB, Davis JM, Koslow SH. Somatic Symptoms in Primary Affective DisorderPresence and Relationship to the Classification of Depression. Arch Gen Psychiatry. 1985;42(11):1098–1104. doi:10.1001/archpsyc.1985.01790340082012