Objective: To analyze new and reviewed findings to evaluate relations between treatment response and latency from onset of bipolar disorder (BD) to the start of mood-stabilizer prophylaxis.
Method: We analyzed our own new data and added findings from research reports identified by computerized searching.
Results: We found 11 relevant studies, involving 1485 adult patients diagnosed primarily with BD. Reported latency to prophylaxis averaged 9.6 years (SD 1.3), and follow-up in treatment averaged 5.4 years (SD 3.1). Greater illness intensity and shorter treatment latency were closely associated, resulting in a greater apparent reduction in morbidity with earlier treatment. However, this finding was not sustained after correction for pretreatment morbidity, and treatment latency did not predict morbidity during treatment. Therefore, assessments based on improvement with treatment, or without correction for pretreatment morbidity, can be misleading.
Conclusions: Available evidence does not support the proposal that delayed prophylaxis may limit response to prophylactic treatment in BD and related disorders.