RecruitingEarly Phase 1Drug trialPsilocybin for Depression in People With Mild Cognitive Impairment or Early Alzheimer's DiseaseThis 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.