Long-term outcome of lithium prophylaxis in bipolar disorder with mood-incongruent psychotic features: a prospective study

Background: No study has assessed systematically up to now the long-term outcome of lithium prophylaxis in bipolar patients with vs. without mood-incongruent psychotic features. Methods: All bipolar patients with mood-incongruent psychotic features who started lithium prophylaxis at a lithium clinic during 14 years were followed up prospectively for 5 years, along with a control group of non-psychotic bipolars. Results: Psychotic patients were significantly less likely than controls to be still on lithium after 5 years, and to present a reduction of at least 50% of time spent in hospital during the lithium treatment period compared with a pre-treatment period of the same duration. The time to 50% risk of readmission was significantly increased among both groups during lithium treatment. 39.6% of prospective episodes in psychotic patients did not include mood-incongruent psychotic features. Limitations: This is a naturalistic study carried out at a lithium clinic. No control group of bipolar patients who did not receive lithium was available. Conclusions: Lithium exerts a significant impact on the course of bipolar disorder with mood-incongruent psychotic features, although this impact is less pronounced than in classical manic-depressive illness.