A Probiotic Intervention to Prevent Relapse Following Hospitalization for Mania

This will be a 24-week, randomized, double-blind, placebo-controlled trial of adjunctive probiotic therapy in 66 persons hospitalized with a manic or mixed episode. The active study compound will consist of capsules containing approximately 10\^9 colony forming units of the probiotic organisms, Lactobacillus GG and Bifidobacteria lactis strain Bb12. The dose has been selected because it has been used safely in other probiotic trials, was well-tolerated by the participants in two previous trials of individuals with schizophrenia or mania, and was utilized in the original trial on which this replication is based. This dose is higher than that available in most commercially-sold health food supplements. Following hospital discharge, participants will be randomized to receive adjunctive probiotic or placebo for a 24 week period. It is anticipated that of the 66 participants randomized, \~50 (75%) will complete the full 24 weeks of the study. The primary outcome is relapse, defined as re-hospitalization (e.g., admission to an inpatient unit) for psychiatric symptoms following a previous hospital discharge by at least 2 weeks. The occurrence of new mood episodes, the severity of psychiatric symptoms, and any changes in cognitive test scores over the course of the study will also be evaluated. Changes in the levels of inflammatory markers as well as changes in gut microbiota will be evaluated at three time intervals over the course of the study.