Despite the advances in biological and psychosocial assessment methods, reliable distinction between depressed patients with endogenous presentations or melancholic symptom features and those with nonendogenous presentations has remained elusive.
Ninety patients with histories of frequent unipolar episodes classified as endogenous or nonedogenous by the Research Diagnostic Criteria were interviewed with the Bedford College Life Events and Difficulties Schedule regarding the 6 months before onset of their most recent episode of depression.
Patients meeting the Research Diagnostic Criteria for definite endogenous subtype differed significantly from patients with nonendogenous features in terms of the proportion experiencing severe life stress in the 6 months before onset of their depressive episode (P<_.04). Furthermore, survival analysis revealed a closer temporal association between severe event and depression onset among patients with nonendogenous features (P<.02).
Even among patients with a history of multiple recurrences of depression, psychological stress plays an important role in the timing of onset of episodes characterized by nonendogenous features.
Frank E, Anderson B, Reynolds CF, Ritenour A, Kupfer DJ. Life Events and the Research Diagnostic Criteria Endogenous SubtypeA Confirmation of the Distinction Using the Bedford College Methods. Arch Gen Psychiatry. 1994;51(7):519-524. doi:10.1001/archpsyc.1994.03950070011005