User perceptions of the benefits and harms of hallucinogenic drug use: A web-based questionnaire study

Abstract

This study used a web-based questionnaire to investigate user perceptions of the benefits and harms of hallucinogenic drug use. Over 600 forms were submitted. Users were asked to comment on the acute and prolonged effects of different drugs and to provide more specific information on how particular drugs have harmed and/or helped them. Subjects reported relatively less harm associated with the classic hallucinogens, LSD and psilocybin, than other drugs specifically focused on in the questionnaire (MDMA, cannabis, ketamine and alcohol). A wide-range of benefits was reported, including: help with mood disorders, addictions and migraine as well as more general long-term improvements in wellbeing. Symptoms of hallucinogen persisting perceptual disorder were reported by a number of subjects and these were most closely associated with use of LSD; however, few users regarded these effects as troubling. Eighty-one per cent of users reported having had a 'spiritual experience' on a hallucinogenic drug and over 90% considered 'access to the unconscious mind' to be a specific property of the classic hallucinogens. With caution, these findings support recent calls for a systematic investigation of the therapeutic potential of the classic hallucinogens and highlight the scope for empirical investigations of spiritual and psychodynamic phenomena.

In the evidence

This study is part of the evidence base for 2 syntheses in the library. Here is how each one recorded it.

• State of the evidence: LSD for addiction ↑Supports

  Users reported less harm from LSD and psilocybin than from several other drugs and reported benefits including help with addictions, though some reported persisting perceptual symptoms.

  Synthesized October 22, 2026

• State of the evidence: MDMA for addiction ↑Supports

  Users reported benefits including help with addictions and mood disorders, and reported less harm from classic hallucinogens than from MDMA, cannabis, ketamine, and alcohol.

  Synthesized October 22, 2026

Comparable studies

Other cross-sectional and survey studies on LSD for addiction, most cited first.