The antidepressants paroxetine and citalopram distinctly outperformed placebo among patients who experienced no adverse effects from the drugs in US Food and Drug Administration (FDA)-registered, placebo-controlled trials, according to a new mega-analysis published online in Molecular Psychiatry.

The findings reject a widely disseminated theory, reported on in media outlets including Newsweek and 60 Minutes, that such medications exert no actual antidepressant effect.

“It has been suggested that the superiority of antidepressants over placebo in controlled trials is merely a consequence of side effects enhancing the expectation of improvement by making the patient realize that he/she is not on placebo,” wrote researchers from the University of Gothenburg, Sweden. “We explored this hypothesis in a patient-level post hoc analysis.”