Table 2.

Summary of clinical research with psychedelics.

Study	Drug (dose) / Design	Total N (no. females) / Diagnosis	Key Findings
Bogenschutz et al., 2015	Psilocybin (0.3 – 0.4 mg/kg) with MET a / open label	10 (4) / Alcohol dependence	Significant reduction in self-reported drinking days and heavy drinking days for 32 weeks after psilocybin administration compared to baseline (p < 0.05).
Carhart-Harris et al., 2016	Psilocybin (10 mg and 25 mg) in a supportive setting, open-label	12 (6) / Treatment-resistant unipolar major depression	Significant reductions in baseline Quick Inventory of Depressive Symptoms (QIDS) scores from one week (p = 0.002; Hedges’ g = 3.1) to 3 months (p = 0.003; Hedges’ g = 2) after 25 mg psilocybin. Beck Depression Inventory (BDI) showed complete remission in 8 (67%) participants at one week, and 5 (42%) participants at 3 months after 25 mg psilocybin,
Gasser et al., 2014a	LSD (200 μg) with psychotherapy / randomized double-blind active placebo (20 μg LSD), cross-over	11 (4) / Anxiety associated with life-threatening illness	Significant reductions in State-Trait Anxiety Inventory (STAI) scores at 2 months post-drug administration, with sustained decrease in STAI scores to 12-month follow-up (p < 0.05).
Grob et al., 2011	Psilocybin (0.2 mg/kg) / randomized double-blind active placebo (niacin)	12 (11) / Anxiety associated with advanced cancer	Significant reductions in STAI trait anxiety at 1 and 3 months post-treatment (p < 0.05). Significant reductions in Beck Depression Inventory scores at 6-months post-treatment (p < 0.05).
Johnson et al., 2014	Psilocybin (20 and 30 mg / 70 kg) with CBT b / open label	15 (5) / Tobacco dependence	Biologically verified smoking abstinence in 80% (n = 12) of volunteers at 6-month follow-up, as assessed by exhaled breath carbon monoxide and urine cotinine levels.
Krebs & Johansen, 2012	LSD (200 – 800 μg) with counseling / meta-analysis of controlled trials	536 (2) / Alcohol dependence	Individuals receiving a single dose of LSD in the context of alcoholism treatment exhibited significantly reduced alcohol misuse at initial follow-up compared with patients receiving non-psychedelic control treatments (OR, 1.96; 95\36–2.84; p = 0.0003)
Moreno et al., 2006	Psilocybin (0.025 – 0.3 mg/kg) / double-blind dose escalation	9 (2) / Obsessive compulsive disorder	Marked reductions on Yale-Brown Obsessive Compulsive Scale (YBOCS) scores for all participants during one or more psilocybin sessions, ranging from 23 – 100% decrease in YBOCS score, with effects generally lasting more than 24 hours post-drug administration.
Osório et al., 2015	Ayahuasca (2.2 mL/kg)1 / open label	6 (4) / Recurrent major depressive disorder	Significant reductions in Hamilton Rating Scale for Depression (HAM-D) and Montgomery-Åsberg Depression Rating Scale (MADRS) scores between baseline and 1, 7, and 21 days after ayahuasca administration.

Note.

^aMET = Motivational Enhancement Therapy.

^bCBT = Cognitive behavioral therapy.

¹Ayahuasca contained: 0.8 mg/mL dimethyltryptamine, 0.21 and mg/mL harmine, and no harmaline.