Pilot Study of Serotonin 2A Receptor (5-HT2A) Agonist Psilocybin for Depression in Patients With Mild Cognitive Impairment or Early Alzheimer's Disease

This open-label pilot study examines whether the hallucinogenic drug, psilocybin, given under supportive conditions, is safe and effective for depression in people with Mild Cognitive Impairment (MCI) or early Alzheimer's Disease (AD). This study will also assess whether psilocybin may improve quality of life in those individuals. This is a pilot study evaluating the potential efficacy of psilocybin to produce improvement in depression compared to pre-treatment in people with Mild Cognitive Impairment (MCI) or early Alzheimer's Disease (AD) and clinically significant symptoms of depression. The study will be an open-label trial in a sample of up to 20 treatment-seeking participants with a diagnosis of MCI or early AD. Participants will complete an 8-week course of study treatment including two psilocybin sessions (15 mg/70 kg in week 4 and 15 or 25 mg/70 kg in week 6), with follow-up assessments up to 6 months after the final psilocybin session. The study will assess changes in depressed mood at 1 week after the second psilocybin session compared to pre-treatment, and quality of life in participants from pre- to post-treatment.