A growing body of preliminary clinical research indicates that psilocybin, a compound found in hallucinogenic fungi, combined with psychological support can improve mood, reduce anxiety, and enhance quality of life. An open-label study showed marked reductions in depression symptoms among participants with treatment-resistant depression. The underlying neurobiological changes include altered brain connectivity and activity in the amygdala and default mode network, as well as increased synaptogenesis and neural plasticity. A randomized, double-blind trial has recently launched across Europe and North America, including a center in Ireland, to further test psilocybin's efficacy for treatment-resistant depression.
The medium- to long-term mental health consequences of COVID-19 are predicted to increase, requiring multidisciplinary strategies. Psilocybin therapy shows promise as a transdiagnostic treatment for disorders with maladaptive habitual patterns, such as depression, addiction, and obsessive compulsive disorder. The COMPASS Pathways phase 2b double-blind trial is testing psilocybin therapy in antidepressant-free treatment-resistant depression (TRD) to determine safety, efficacy, and optimal dose. Results from the Imperial College London Psilodep-RCT comparing psilocybin therapy to the SSRI escitalopram will soon be published. The efficacy and safety of psilocybin therapy with SSRIs in TRD is not yet known; a COMPASS study in Dublin will address this. Psilocybin therapy may play an important role in post-COVID-19 psychiatry, though it is at an early clinical stage.