Meta-correlation of the effect of ketamine and psilocybin induced subjective effects on therapeutic outcome.
Npj mental health research – October 06, 2024
Source: PubMed
Summary
Psychedelic experiences during ketamine and psilocybin therapy may influence healing, but their importance varies. Analysis of 654 patients across multiple studies revealed that subjective effects during treatment explained about 5-10% of ketamine's therapeutic benefits and 24% of psilocybin's benefits. The healing impact was stronger for addiction treatment than depression, with psilocybin showing more connection between experience and outcome.
Abstract
There is some evidence that the subjective effects of ketamine and other psychedelics like psilocybin are crucial for their therapeutic outcomes, such as treatment of depression or substance use disorder (SUD). We performed a meta-analysis and systematic review on the correlation of subjective symptoms and dissociation versus ketamine-induced therapeutic outcomes in patients with depression or SUD. A similar analysis was conducted for psilocybin-induced therapeutic improvement. We retrieved 23 papers studying ketamine (21 on depression, 2 on SUD) in 471 patients and 8 papers studying psilocybin (6 on depression, 2 on SUD) in 183 patients. Our study demonstrated a modest role for subjective effects mediating therapeutic outcomes, with R2-values ranging from 5-10% for ketamine and for psilocybine the R2 was 24%. A greater mediating effect for psilocybin compared to ketamine was detected, particularly when restricting the analysis to depression. Additionally there is a greater mediating effect in SUD than depression, irrespective of treatment.