Psilocybin-Enhanced Psychotherapy for Methamphetamine Use Disorder

Inclusion Criteria: * United States military Veteran * Moderate to severe methamphetamine use disorder using the DSM-V diagnostic criteria * Desire to cease or reduce methamphetamine use Exclusion Criteria: * Have uncontrolled hypertension or clinically significant cardiovascular disease * History of seizure disorder in adulthood * CNS metastases or symptomatic central nervous system (CNS) infection * Poorly controlled diabetes mellitus * Taking certain medications that may interact with psilocybin * History of any primary persistent psychotic disorder, including schizophrenia, schizoaffective disorder, bipolar disorder with psychosis, major depressive disorder with psychosis, or schizophreniform disorder * History of bipolar I disorder * Current eating disorder with active purging * History of hallucinogen use disorder * Pregnant or breast feeding