THE LIKELIHOOD OF RECURRENCE IN BIPOLAR AFFECTIVE-DISORDER - THE IMPORTANCE OF EPISODE RECENCY

These analyses used a high-intensity follow-up of of patients with bip olar affective disorder to describe the immediate and long-term risks for recurrence and the importance of sustained recovery to those risks . At the baseline evaluation, all patients were in episodes of Researc h Diagnostic Criteria major depressive disorder, mania or schizoaffect ive disorder (excluding the mainly schizophrenic subtype); those who w ere depressed at intake had a history of mania or schizoaffective mani a. Raters re-evaluated these patients at 6-month intervals for 5 years and annually for the remainder of a 10-year follow-up. The following report describes relapse risks for the 186 patients observed to recove r from their index episodes. Survival analyses quantified the likeliho od of relapse over time, beginning after symptom-free periods of 4 mon ths and 1, 2 and 3 years. Further survival analyses used treatment sta tus as a censoring variable to estimate the eventual likelihood of rec urrence among those who reported sustained compliance with lithium pro phylaxis; the prophylaxis group remained under observation until they relapsed, were lost to follow-up or ceased taking lithium. Progressive ly longer symptom-free periods were clearly associated with lower rela pse risks over the subsequent 4 years. Thereafter, however, this effec t dissipitated. 7 years after recovery, the cumulative likelihood of r ecurrence was four in five for all bipolar patients and two in three f or those whose index episode had been followed by at least 3 years wit hout symptoms. Even with sustained lithium prophylaxis, the likelihood of at least one recurrence exceeded 70% within 5 years of recovery. T he preexisting length of symptom-free periods in bipolar affective dis order can be used to predict risks for recurrence over a subsequent 4- year period. The eventual likelihood of recurrence remains quite high though, even with lithium prophylaxis.