Psychedelic-Assisted Therapy May Reduce Anxiety and Depression in Patients with Life-Threatening Diseases
20 Oct, 2024 | 18:02h | UTCBackground: Anxiety, depression, and existential distress are prevalent among individuals facing life-threatening illnesses, significantly impacting their quality of life. Traditional treatments often have limited efficacy in this population. Psychedelic-assisted therapy, involving substances like psilocybin and LSD under professional supervision, has been proposed as a potential intervention. However, these substances are illegal in most countries and pose potential risks.
Objective: To assess the benefits and harms of psychedelic-assisted therapy compared to placebo or active comparators in treating anxiety, depression, and existential distress in people with life-threatening diseases.
Methods: This Cochrane systematic review included six randomized controlled trials conducted in the USA and Switzerland between 2011 and 2022. A total of 149 participants (140 analyzed), aged 36 to 64 years with life-threatening illnesses (e.g., cancer), were randomized to receive psychedelic-assisted therapy using classical psychedelics (psilocybin or LSD) or MDMA. Interventions included preparatory sessions, the psychedelic experience, and integration sessions. Comparators were active placebos (e.g., low-dose psychedelic or niacin) or placebo. Primary outcomes were anxiety, depression, and existential distress measured 1 to 12 weeks post-intervention.
Results: Psychedelic-assisted therapy with classical psychedelics may reduce anxiety and depression compared to active placebo:
- Anxiety: Mean difference (MD) of −8.41 points on the STAI-Trait scale (20–80 range; 95% CI, −12.92 to −3.89; 5 studies, 122 participants; low-certainty evidence).
- Depression: MD of −4.92 points on the Beck Depression Inventory (0–63 range; 95% CI, −8.97 to −0.87; 4 studies, 112 participants; low-certainty evidence).
The effect on existential distress was mixed and very uncertain. No treatment-related serious adverse events or grade 3/4 adverse events were reported. Common mild to moderate adverse events included elevated blood pressure, nausea, anxiety, and transient psychotic-like symptoms, which resolved shortly after the sessions.
Conclusions: Psychedelic-assisted therapy with classical psychedelics may reduce symptoms of anxiety and depression in patients with life-threatening diseases, but the evidence is of low certainty due to methodological limitations and small sample sizes. The effects of MDMA-assisted therapy are very uncertain.
Implications for Practice: While findings are promising, clinicians should exercise caution due to the low certainty of evidence and legal restrictions surrounding psychedelic substances.
Study Strengths and Limitations: Strengths include randomized designs and standardized therapeutic protocols involving preparation and integration sessions. Limitations are high risk of bias due to unblinding, small sample sizes, potential expectation bias, and cross-over designs with carry-over effects.
Future Research: Larger, well-designed RCTs with rigorous blinding are needed to confirm these findings. Future studies should explore long-term outcomes, diverse patient populations, and strategies to mitigate bias, such as using active placebos and measuring expectancy effects.