Psilocybin - Induced Neuroplasticity in the Treatment of Major Depressive Disorder

The primary goal of this pilot study is to investigate whether psilocybin alters neuroplasticity in people with major depressive disorder. The primary hypothesis is that psilocybin will result in neuroplastic changes that parallel improvement in symptoms of depression. In this placebo-controlled, blinded study, individuals with depression will participate in 2 experimental sessions approximately 4 weeks apart during which they will receive two of the following three interventions: 1) placebo, 2) low dose psilocybin (0.1 mg/kg), and 3) medium dose psilocybin (0.3 mg/kg).