Treatment-latency and previous episodes: relationships to pretreatment morbidity and response to maintenance treatment in bipolar I and II disorders.

OBJECTIVE: To clarify relationships of treatment delay and pretreatment episode count with pretreatment morbidity and responses to maintenance treatments in bipolar disorders.
METHODS: In 450 DSM-IV bipolar I (n = 293) or II (n = 157) patients (280 women, 170 men), we evaluated correlations of latency from illness-onset to starting maintenance treatment and pretreatment episode counts with pretreatment morbidity and treatment response. We considered morbidity measures before and during treatment, and their differences.
RESULTS: Latency averaged 7.8 years, with 9.0 episodes per patient, before various maintenance treatments started. Morbidity (percentage of time-ill, episodes per year, first wellness-interval, or proportion of subjects hospitalized or having no recurrences) during maintenance treatment averaging 4.2 years was unrelated to treatment latency or pretreatment episode count. However, pretreatment morbidity was greater with shorter latency, resulting in larger relative reduction of morbidity after earlier treatment.
CONCLUSIONS: Greater treatment latency and pretreatment episode count were not followed by greater morbidity during treatment, although longer delay yielded smaller during-versus-before treatment reduction in morbidity. Predictions that longer treatment delay or more pretreatment episodes lead to poorer responses to various maintenance treatments in bipolar I or II disorder were not supported.