The Efficacy of Psychostimulants in Major Depressive Episodes: A Systematic Review and Meta-Analysis
Psychostimulants are frequently prescribed off-label for adults with major depressive disorder or bipolar disorder. The frequent and increasing usage of stimulants in mood disorders warrants a careful appraisal of the efficacy of this class of agents. Herein, we aim to estimate the efficacy of psychostimulants in adults with unipolar or bipolar depression.Methods
The PubMed/Medline database was searched from inception to January 16, 2016 for randomized, placebo-controlled clinical trials investigating the antidepressant efficacy of psychostimulants in the treatment of adults with unipolar or bipolar depression.Results
Psychostimulants were associated with statistically significant improvement in depressive symptoms in major depressive disorder (odds ratio [OR], 1.41; 95% confidence interval [CI], 1.13–1.78; P = 0.003) and bipolar disorder (OR, 1.42; 95% CI, 1.13–1.78; P = 0.003). Efficacy outcomes differed across the psychostimulants evaluated as a function of response rates: ar/modafinil (OR, 1.47; 95% CI, 1.20–1.81; P = 0.0002); dextroamphetamine (OR, 7.11; 95% CI, 1.09–46.44; P = 0.04); lisdexamfetamine dimesylate (OR, 1.21; 95% CI, 0.94–1.56; P = ns); methylphenidate (OR, 1.49; 95% CI, 0.88–2.54; P = ns). Efficacy outcomes also differed between agents used as adjunctive therapy (OR, 1.39; 95% CI, 1.19–1.64) or monotherapy (OR, 2.25; 95% CI, 0.67–7.52).Conclusions
Psychostimulants are insufficiently studied as adjunctive or monotherapy in adults with mood disorders. Most published studies have significant methodological limitations (eg, heterogeneous samples, dependent measures, type/dose of agent). In addition to improvements in methodological factors, a testable hypothesis is that psychostimulants may be more appropriately tested in select domains of psychopathology (eg, cognitive emotional processing), rather than as “broad-spectrum” antidepressants.