Psilocybin for Depression in People With Mild Cognitive Impairment or Early Alzheimer's Disease

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.