Adjunctive treatment with psychostimulants and stimulant-like drugs for resistant bipolar depression: a systematic review and meta-analysis

Background Depression is considered to be the most difficult to treat phase of bipolar disorder as patients experience residual symptoms causing long-term disability. This work aims to explore the role of add-on stimulant and stimulant-like medication in resistant bipolar depression patients. Methods Systematic review of add-on stimulants and stimulant-like drugs in resistant bipolar depression by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Analysis was performed using the random-effects models. Heterogeneity was evaluated with Cochran's Q and I-2 statistics. Results Six randomized controlled trials of add-on modafinil, armodafinil, and lisdexamphetamine (LDX) (n = 813) vs placebo (n = 815) in the treatment of resistant bipolar depression were included. These drugs were more likely to induce remission from an episode of resistant bipolar depression (relative risk [RR] = 1.37; 95% confidence interval [CI]: 1.06-1.77; number needed to treat for an additional beneficial outcome = 16). Moreover, they did not induce more dropouts than placebo (RR = 1.04; 95% CI: 0.91-1.18), nor did they increase the risk of adverse effects (53/772 vs 41/771) at the end of treatment (RR = 1.30; 95% CI: 0.81-2.10; number needed to treat for an additional harmful outcome = 62). Suicidality and manic switch were not affected by active treatment. Heterogeneity was low (Cochran's Q: P > .05), but sometimes with a large CI. Conclusions LDX, modafinil, and armodafinil seem to offer a reasonably well-tolerated and safe treatment in resistant bipolar depression. Treatment guidelines should, therefore, be revised to include these medications earlier in the therapeutic algorithm for resistant acute bipolar depression. Further research is, however, necessary for the elucidation of the clinical usefulness of these and other similar compounds.