Objective: This study investigated the impact of latency (the time between illness onset and initiation of prophylactic treatment) on the outcome of prophylaxis in bipolar disorders.
Method: The effect of prophylaxis delay (latency) on the course of illness was assessed in 147 patients. Dependent variables were: reduction of days spent in the hospital (prior to vs. during prophylaxis), time to first recurrence, and Morbidity-Index during prophylaxis (lithium or carbamazepine). Latency and other independent variables were tested using a multivariate approach.
Results: Latency (9.3 years on average) had no significant effect on the subsequent response. Illness severity prior to prophylaxis, however, did predict the relative response. The course of illness during treatment could not be predicted by any one factor.
Conclusion: The delay in initiating prophylaxis appears to have no influence on prophylaxis outcome. Instead, those whose illness was more severe were treated earlier and these patients subsequently showed a relatively greater response. If severity is not controlled for as part of the analysis, latency may be mistaken as an important predictor for response.