Scientists admit SSRIs' mechanisms remain murky as debate over overuse intensifies

Even after decades of prescription, scientists have not fully mapped how selective serotonin reuptake inhibitors produce therapeutic effects, citing influences on neural pathways, stress hormones, inflammation and gene activity. Experts like Maurizio Fava and Catherine Harmer note that depression lacks a single biological route, leading to varied individual responses. The issue resurfaced at a mental-health summit when US Secretary of Health Robert F. Kennedy Jr warned that SSRIs are overused and that withdrawal symptoms can be as severe as heroin addiction, sparking backlash and some agreement among clinicians.

Critics argue his statements could scare people away from effective treatment, whereas supporters point to a real public-health challenge given that roughly one in six U.S. adults take antidepressants. New research tools are beginning to connect symptom changes with underlying biology, a shift likened to breakthroughs in 1990s cancer research. Nonetheless, fundamental questions about depression’s neurobiology and SSRIs’ precise actions remain unanswered.