SSRI Reduces Negative Effects of Psilocybin, With No Impact on Positive Mood Effects in Study

MindMed has published results of a study it sponsored to examine the interaction of the selective serotonin uptake inhibitor (SSRI) escitalopram with the acute response to psilocybin in humans. The study was a randomized, double-blind, placebo-controlled, crossover pharmacology study in healthy volunteers that was conducted by the University Hospital Basel Liechti Lab.

Findings were published in the journal Clinical Pharmacology and Therapeutics.

Escitalopram was found pre-treatment to have no relevant impact on psilocybin’s positive mood effects, but significantly reduced negative effects, such as anxiety and adverse cardiovascular reactions compared with a placebo.

“Two key questions arise around the use of psilocybin in patients undergoing antidepressant treatment," said Matthias Liechti, principal investigator of the study, said in a news release. "First, for safety reasons, should a patient stop using antidepressants before receiving psilocybin? Second, if there is no safety risk, will the antidepressant reduce the patient's response to psilocybin?

“These results indicate that psilocybin may be dosed during escitalopram treatment without apparent impact on the effect of psilocybin. Thus, the study answers the first question and provides a positive indication for the second.”

MindMed president Miri Halperin Wernli, PhD, said in the release that if the study’s results are confirmed in future research that involves patients instead of healthy individuals, it could indicate that antidepressants may no longer need to be stopped prior to receiving psilocybin-involved treatments.