Blunted psychedelic drug effects in older adults

Classic psychedelic drugs, including psilocybin, lysergic acid diethylamide, and ayahuasca/N,N-dimethyltryptamine, are increasingly being studied as therapeutics for myriad health conditions; however, predicting individual responses is notoriously difficult. An arguably underappreciated variable potentially moderating responses to psychedelics is age. Older adults exhibit unique pathogenesis of various neuropsychiatric disorders and, accordingly, have unique treatment considerations. In the case of psychedelics, differences in life circumstances, peripheral physiology, polypharmacy, weight, and neurobiology may present unique theoretical risks and opportunities for older adults. Here, we overview increased interest in studying psychedelics in older adults and spotlight an overlooked but consistent trend that has emerged in the literature-blunted psychedelic drug effects across the lifespan.