OBJECT: Pharmacotherapy oftentimes proves inadequate in providing satisfactory prophylaxis for affective disorders; thus the need for alternative interventions is obvious. In this observational study, the effectiveness of three non-pharmacological methods employed in patients with recurrent affective illness for prophylaxis in a case series of depressed patients is reported. METHOD: (a) Electroconvulsive therapy (ECT) was administered twice and later once a month for a period of 2-35 months in nine ECT-recovered depressed patients. (b) Sleep deprivation (SD) was applied once a week for 9-12 months in six SD-recovered depressed patients. (c) Cognitive therapy (CT)-recovered depressed patients (n=10) received additional CT "booster sessions" every 4 weeks, for 6-8 months. RESULTS: Eight patients in the ECT study and four in the SD study remained in remission during the period of the prophylactic intervention. No significant side-effects for the two methods were observed. Regarding CT, eight patients were not reported as depressed at the 24-month follow-up period. CONCLUSION: These clinical observations support the current view about the utility of the three non-pharmacological interventions in the prophylaxis of affective disorders, since all methods displayed a satisfactory clinical profile. [ABSTRACT FROM AUTHOR]