Adjunct treatments for schizophrenia and bipolar disorder: what to try when you are out of ideas.

The pharmacologic treatment of schizophrenia and bipolar disorder leaves much to be desired. Repurposed drugs, which are approved for other medical conditions, represent an underutilized therapeutic resource for patients who have not responded to other drugs. Using experience gained from a decade of repurposed drug studies by the Stanley Medical Research Institute and search of the literature, we have identified nine such drugs for which there is some evidence of efficacy for schizophrenia and/or bipolar disorder. These include: aspirin; celecoxib; estrogen/raloxifene; folate; minocycline; mirtazapine; omega-3 fatty acids; pramipexole; and, pregnenolone. The evidence of efficacy is reviewed for each drug. Because there is little or no financial incentive for pharmaceutical companies to promote such drugs, there is a paucity of definitive trials, and these drugs are less widely known than they deserve to be. Biomarker studies should also be carried out to identify subgroups of patients who do respond to these drugs.