Translated from our German original by AI. The German text was researched, written, and edited by the Psychedelia Foundation team and remains the authoritative version.
A review published in the Journal of Psychopharmacology challenges a common assumption: that the controlled studies of psychedelic therapy from the 1960s and 1970s carry little weight because they were methodologically weak. Torsten Passie and Michiel van Elk analyzed eleven controlled trials conducted in the United States and Canada between 1965 and 1977. The participants included people with alcohol and opioid use disorders and people with psychoneuroses.
The authors judge those studies to have been comparatively advanced for their time. Several used blinding, active control conditions, comparison groups and long-term follow-up. The statistical reporting, however, was in places far less detailed than today’s standards require.
The re-evaluation gives a largely sobering picture of how durable a classic psychedelic “peak therapy” is. Across a range of study designs, most of the trials found no significant long-term differences between the psychedelic and the control groups. Some did show improvements immediately after treatment or in the first months, but at later follow-ups those improvements often could no longer be clearly attributed to the psychedelic treatment.
There were individual positive findings. In one study of patients with opioid dependence, 25 percent of the LSD group were abstinent after twelve months, compared with five percent of the control group. General social adjustment, by contrast, showed no significant difference.
The authors read this above all as an indication that one or a few high-dose sessions aimed at a “peak experience” may not be enough to produce lasting therapeutic change in chronic conditions. A mystical experience on its own, they argue, should not be treated as a sufficient mechanism of action.
The positive “afterglow” phase that follows a psychedelic experience could instead be a therapeutic window, one in which psychotherapeutic work can be supported particularly effectively. The authors accordingly call for a stronger psychotherapeutic framework, and see psychedelics as a possible support for psychotherapy rather than a replacement for it.
In context: the paper does not rule out the possibility of long-term therapeutic effects from psychedelics. What it shows is that the historical controlled studies produced no convincing evidence of lasting effects for one particular model, a short course of treatment built around a peak experience in chronic conditions. From that the authors draw conclusions for how psychedelic therapies are designed today.
