Low dose of caffeine enhances the efficacy of antidepressants in major depressive disorder and the underlying neural substrates. - PubMed - NCBI
A total of 95 male inpatients were assigned to three groups and were asked to take either caffeine (60, 120mg) or placebo (soymilk powder) daily for 4 weeks on the basis of their current antidepressant medications. Results showed that chronic supplementation with low dose of caffeine (60 mg) produced rapid antidepressant action by reduction of depressive scores. Furthermore, low dose of caffeine improved cognitive performance in depressed patients.