Table 1. Use of psilocybin in the treatment of addiction to nicotine, alcohol, methamphetamine, cocaine, and opioids.

CBT: cognitive behavioral therapy; AUD: alcohol use disorder: MET: motivational enhancement therapy; OUD: opioid use disorder

Substance	Study design	Participants	Treatment regimen	Results	Follow-up
Nicotine [16]	Open-label, pilot study	15 adult smokers	CBT, 20 mg/70 kg psilocybin at fifth week, 30 mg/70 kg psilocybin at seventh week, optional 30 mg/70 kg psilocybin at 13th week	80% of participants were abstinent at six months, 60% of participants were continuously abstinent through six months	60% of participants were continuously abstinent at 12 months, 75% of participants were abstinent at long-term follow-up (mean: 30 months) [17]
Alcohol [20]	Open-label, pilot study	10 adults with AUD	MET, 0.3 mg/kg psilocybin, 0.4 mg/kg (or 0.3 mg/kg if preferred by the participant) psilocybin	Compared to baseline, 26% mean decrease in percent heavy drinking days following first psilocybin session, 27% mean decrease in the percent of days when subjects consumed alcohol, a significant decrease in PACS value	None to date
Methamphetamine [23]	Interventional, randomized trial	30 adults with amphetamine-related disorders	Experimental group: six-week psychotherapy protocol, 25 mg, and 30 mg psilocybin administrations two weeks apart; control group: treatment-as-usual while admitted to an inpatient rehabilitation program	Pending; estimated completion date: June 30, 2024	Pending
Cocaine [24]	A double-blinded, randomized, controlled trial	40 adults with cocaine-related disorders	Experimental group: 0.36 mg/kg psilocybin; comparator group: 100 mg diphenhydramine	Pending; estimated completion date: April 2022	Pending
Opioids [25]	Open-label, pilot study	10 adults with OUD	Two administrations of psilocybin with guided counseling, approximately four weeks apart	Pending; estimated completion date: August 2022	Pending