Table 1.
Authors, objectives, conditions, designs, participants, and treatments of the studies.
| Author | Objective | Condition 1 | Design | Participants | Treatment |
|---|---|---|---|---|---|
| Ross et al., 2016 [9] |
To study the effects of psilocybin therapy on cancer patients with depressive and anxious symptoms. | D&A | Double-blind, controlled, randomized, crossover | - Group 1 (first placebo/second psilocybin): N = 15 (27% men, 73% women). Mean age: 60.27 - Group 2 (first psilocybin/second placebo): N = 14 (50% men, 50% women). Mean age: 52 - Total N = 29 (18 men, 11 women). Mean age: 56.28 |
Three preparatory sessions (4 weeks) to establish therapeutic alliance. Then, two dosing sessions (alternating psilocybin or placebo) with psychotherapy separated by 7 weeks, supported by therapists with a non-directive and supportive attitude. Between doses, three integration sessions (total of 6 h) were conducted. Finally, three additional integrative sessions (total of 6 h) were conducted after the second dose, over a period of 6 weeks. |
| Carhart-Harris et al., 2016 [11] |
To study the feasibility, safety, and efficacy of psilocybin in patients with major depressive disorder. | MDD (TR) | Open-label | N = 12 (6 men, 6 women). Mean age: 42.7 |
One preparatory session (4 h), followed by two doses with music therapy, separated by one week. After each dose, an integrative session was conducted. |
| Giffiths et al., 2016 [10] |
To study the effects of psilocybin therapy on cancer patients with depressive and anxious symptoms. | D&A | Double-blind, controlled, randomized, crossover | - Group 1 (first high dose/second low dose): N = 25 (52% men, 48% women). Mean age: 56.1 - Group 2 (first low dose/second high dose): N = 26 (50% men, 50% women). Mean age: 56.5 - Total N = 51 (51% men, 49% women). Mean age: 56.3 |
Three preparatory sessions, followed by two doses of psilocybin (alternating high and low) separated by 5 weeks, and six sessions for dialogue and analysis of the experience with psilocybin (three between doses and three after the second dose). |
| Lyons & Carhart-Harris, 2018 [12] | To investigate the effects of a psilocybin intervention on pessimistic biases in patients with treatment-resistant depression. | MDD (TR) | Open-label, controlled trial (mixed model) | - Control group (healthy): N = 15 (60% men, 40% women). Mean age: 37.6 - Experimental group (depressed): N = 15 (73.3% men, 26.7% women). Mean age: 45.4 - Total N = 30 (66.7% men, 33.3% women). Mean age: 41.5 |
One preparatory session (4 h), followed by two doses with music therapy, separated by one week. After each dose, an integrative session was conducted. |
| Carhart-Harris et al., 2018 [13] |
To study the efficacy and safety of psilocybin therapy for depression over a period of 6 months. | MDD (TR) | Open-label | N = 20 (14 men, 6 women). Mean age: 42.2 |
One preparatory session (4 h), followed by two doses with music therapy, separated by one week. After each dose, an integrative session was conducted. |
| Carhart-Harris et al., 2021 [14] | To compare psilocybin treatment with escitalopram treatment. | D&A | Double-blind, controlled randomized | - Escitalopram group: N = 29 (20 men, 9 women). Mean age: 39.1 - Psilocybin group: N = 30 (19 men, 11 women). Mean age: 43.3 - Total N = 59 (39 men, 20 women). Mean age: 41.2 |
Six weeks of treatment with six sessions: the first one for preparation before the first dose; the second one for taking the first dose; the third one for exploring the experience during the first dose; the fourth one for taking the second dose; the fifth one for psychological integration of the doses; and the sixth one for exploring the treatment experience. |
| Davis et al., 2021 [2] |
To investigate the effect of psilocybin therapy in patients with major depressive disorder. | D&A | Controlled, randomized | - First group (immediate treatment): N = 13 (5 men, 9 women). Mean age: 43.6 - Second group (delayed treatment): N = 11 (4 men, 7 women). Mean age: 35.2 - Total N = 24 (8 men, 16 women). Mean age: 39.8 |
Eight weeks of intervention: three weeks of preparatory sessions for the doses (8 h total), two sessions with doses in weeks 3 and 4 of treatment along with music therapy, and two integration sessions (2–3 h) after each dose. One group received immediate treatment with psilocybin, and the other received treatment after 8 weeks (at the end of the first group), to differentiate the psilocybin intervention from spontaneous improvement. |
| Gukasyan et al., 2022 [15] | To study the efficacy and safety of psilocybin therapy over 12 months. | D&A | Controlled, randomized | - First group (immediate treatment): N = 13 (5 men, 9 women). Mean age: 43.6 - Second group (delayed treatment): N = 11 (4 men, 7 women). Mean age: 35.2 - Total N = 24 (8 men, 16 women). Mean age: 39.8 |
Eight weeks of intervention: three weeks of preparatory sessions for the doses (8 h in total), two sessions with doses in weeks 3 and 4 of treatment along with music therapy, and two integration sessions (2–3 h) after each dose. One group underwent immediate treatment with psilocybin, and the other group underwent treatment after 8 weeks (at the end of the first group’s treatment), to differentiate psilocybin intervention from spontaneous improvement. |
1 MDD: major depressive disorder; TR = treatment resistant; D&A = depression and anxiety.