Research findings suggest that psychedelic drug use is only weakly associated with psychosis-like symptoms

There has been a recent research article into psychedelics and mental health. A new study finds that psychedelic drug use is only weakly associated with schizotypy and evidence integration impairment typically observed in psychosis-spectrum disorders. This reassuring finding comes from a study published in the journal Scientific Reports, which further found improved evidence integration and greater flexibility of fear learning with psychedelic exposure.

In this study it was discovered that people who take psychedelics are more likely to report psychosis-like symptoms, but this is largely explained by the presence of other mental health conditions and the use of other psychoactive drugs.

Abstract

Despite recently resurrected scientific interest in classical psychedelics, few studies have focused on potential harms associated with abuse of these substances. In particular, the link between psychedelic use and psychotic symptoms has been debated while no conclusive evidence has been presented. A young, health, adult population was studied to evaluate the association of psychedelic drug use with schizotypy. They were also assessed for evidence integration impairment typically observed in psychosis-spectrum disorders. Findings suggest that psychedelic drug use is only weakly associated with psychosis-like symptoms, which, in turn, is to a large extent explained by psychiatric co-morbidities and use of other psychoactive substances. The results also suggest that psychedelics may have an effect on flexibility of evidence integration and aversive learning processes. This may be linked to recently suggested therapeutic effects of psychedelic drugs in non-psychotic psychiatric populations.

Method

The researchers distributed a survey to 1,032 Swedish adults, of whom 701 were between the ages of 18 and 35. Participants had no psychiatric diagnoses and no history of brain trauma. The questionnaire included a measure of schizotypy. Schizotypy is a personality trait that includes schizophrenia-like characteristics such as disorganised thinking and paranoid thoughts.

Results

When comparing psychedelic users to non-users, average schizotypy scores among users were significantly higher, but the effect size was small. Furthermore, when looking exclusively at the subsample of healthy participants, the effect was only marginally significant. Finally, when taking co-occurring drug use into account, the effect of psychedelic use on schizotypy was no longer significant among either sample.

A follow-up survey among a subsample of 197 participants examined drug use patterns. The survey found no evidence of heightened schizotypy among those with greater exposure to psychedelics. However, the use of stimulants (cocaine, amphetamines, ephedrine) was a robust predictor of higher schizotypy.

There were some surprising results in that psychedelic exposure actually predicted lower Evidence Integration Impairment scores. While the use of stimulants predicted greater Evidence Integration Impairment. Evidence Integration Impairment (EII) is the “lack of ability to modify beliefs when facing new information.” These results, the authors say, “support the rationale of psychedelic-assisted therapy for non-psychotic psychiatric conditions characterized by overly fixed cognitive styles, such as, for example, depression.”

The participants also completed a reversal learning task that measured their fear responses to a conditioned stimulus that was sometimes presented with a mild electric shock, according to changing rules. After controlling for co-occurring drug use, people with greater overall psychedelic exposure showed higher sensitivity to instructed knowledge. This result is suggesting greater flexibility of fear learning. Lebedev et al., say that this may suggest that psychedelics can “augment top-down fear learning in a lasting way, which, in turn, may explain their particular efficacy in treating anxiety and trauma-related psychiatric disorders.”

Conclusion

The paper concludes with this statement - “Our analyses did not support the hypothesis that psychedelics may pose serious risks for developing psychotic symptoms in healthy young adults,”. The authors say, although they specify that, “the lack of a strong relation between use of psychedelics and psychosis-associated symptoms does not preclude that such drugs are detrimental for individuals with a high risk of developing psychotic disorders. The authors felt it is an important question that needs to be investigated in future studies.

Lebedev, A.V., Acar, K., Garzón, B. et al. Psychedelic drug use and schizotypy in young adults. Sci Rep 11, 15058 (2021). https://doi.org/10.1038/s41598-021-94421-z

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