DO PSYCHOTIC, MINOR AND INTERMITTENT DEPRESSIVE-DISORDERS EXIST ON A CONTINUUM

The following paper uses information from a family study and 10-year f ollow-up of probands with unipolar depression to describe relationship s between psychotic and non-psychotic major depressive disorder (MDD) and, in turn, between psychotic MDD and minor or intermittent depressi ve disorders. Probands began follow-up as they sought treatment for MD D at any of five participating academic centers. Follow-up evaluations then occurred at 6-month intervals for 5 years and then annually for an additional 5 years. Two-thirds of the probands also entered a famil y study in which raters attempted direct interviews of all available a dult first-degree relatives. Findings that individual symptoms compris ing the endogenous MDD subtype had higher severity ratings, that the f ull MDD syndrome was present for a greater number of weeks in each yea r of follow-up, and that time to new episodes of MDD were shorter, all indicated that patients with psychotic features had a severe variant of MDD. An increased familial risk for psychotic MDD per se, and a sus tained tendency for psychotic features to recur, indicated an importan t discontinuity, however. The increase in morbidity over time which ch aracterized psychotic patients manifested in the full MDD syndrome, bu t not in mild MDD, minor or intermittent depressive syndromes. These m ilder syndromes tended to be more prominent over time among patients w ho began with non-psychotic MDD. This fails to support a continuum spa nning both psychotic MDD and the mild, subsyndromal forms of unipolar depression. (C) 1997 Elsevier Science B.V.