THE PROPHYLAXIS OF DEPRESSIVE EPISODES IN RECURRENT DEPRESSION FOLLOWING DISCONTINUATION OF DRUG-THERAPY - INTEGRATING PSYCHOLOGICAL AND BIOLOGICAL FACTORS

Models of long-term treatment in recurrent unipolar illness ideally sh ould integrate both psychological and biological factors. In earlier r eports we noted that high treatment specificity (i.e. good-quality mai ntenance interpersonal psychotherapy) and high delta sleep ratio were each associated with significantly increased wellness intervals in the absence of pharmacotherapy among patients with recurrent unipolar dep ression. To determine how these specific factors when taken together a re related to length of survival time, we examined the concurrent effe cts of treatment specificity and delta sleep ratio on wellness interva ls using survival analysis. We found significant effects of both treat ment specificity and delta ratio on survival time. Seventy-three per c ent of the patients in the high treatment specificity/high delta ratio group survived the 3-year trial, while 44% of the patients in the low delta ratio but high treatment specificity group survived. None of th ose rated low on both variables survived. We also found an effect for individual clinicians on treatment specificity and survival time and n oted that the prophylactic effect of treatment specificity was maintai ned even within subsets of therapists grouped by their patients' survi val times. Secondary analyses revealed an effect of patient attitudes on treatment specificity and survival time, although, when taken toget her, treatment specificity was the only variable remaining significant ly associated with outcome. We conclude that patients remain well the longest when pre-treatment delta sleep parameters more closely approxi mate those of non-depressed individuals and when monthly psychotherapy is of higher quality. The key finding is that high specificity is of significant prophylactic benefit even for patients with a biological v ulnerability for recurrence. We also conclude that in addition to ther apists, patient expectancies contribute to treatment specificity, and high treatment specificity is, in turn, reflected in longer times to r ecurrence.