Serotonergic hallucinogens and recognition of facial emotion expressions: a systematic review of the literature
Juliana Mendes Rocha, Flávia de Lima Osório, José Alexandre S. Crippa, José Carlos Bouso, Giordano Novak Rossi, Jaime E. C. Hallak, Rafael G. Dos Santos
Therapeutic Advances in Psychopharmacology January 1, 2019 DOI: 10.1177/2045125319845774 via OpenAlex
Summary
AI-generated from the abstractA systematic review of 8 studies found that serotonergic hallucinogens such as LSD and psilocybin reduce the recognition of negative emotions in facial expressions and modulate amygdala activity in response to these stimuli. These effects correlated with antidepressive benefits in patients. The drugs were well tolerated. Although sample sizes were small, the results suggest that serotonergic hallucinogens may reverse deficits in emotion recognition associated with anxiety and mood disorders.
Study at a glance
| Characteristics | Systematic review Randomized Peer reviewed |
|---|---|
| Interventions | LSD psilocybin |
| Topics | Psilocybin Serotonin |
| Keywords | Hallucinogen Facial expression Cognitive psychology |
| Citations | 44 |
| Key finding | Serotonergic hallucinogens reduce recognition of negative emotions and modulate amygdala activity, correlating with antidepressive effects. |
Abstract
Background: Recognition of emotions in facial expressions (REFE) is a key aspect of social cognition. Anxiety and mood disorders are associated with deficits in REFE, and anxiolytics and antidepressants reverse these deficits. Recent studies have shown that serotonergic hallucinogens (i.e. ayahuasca, dimethyltryptamine, psilocybin, lysergic acid diethylamide [LSD], and mescaline) have anxiolytic and antidepressant properties, but their effects on REFE are not well understood. The purpose of the study was to conduct a systematic review analyzing the effects of serotonergic hallucinogens on REFE in humans. Methods: Studies published in the PubMed, PsycINFO, and Web of Science databases until 19 October 2018 which analyzed the effects of serotonergic hallucinogens on REFE in humans were included. Results: Of the 62 studies identified, 8 studies were included. Included studies involved the administration of a single or a few doses of LSD or psilocybin, and most trials were randomized and controlled with placebo. LSD and psilocybin reduced the recognition of negative emotions in most studies and modulated amygdala activity to these stimuli, which was correlated with antidepressive effects in patients. Both drugs were well tolerated. Conclusions: Serotonergic hallucinogens reduced the recognition of negative emotions by modulating amygdala activity. Despite the small sample sizes, results suggest that serotonergic hallucinogens show promising beneficial effects on deficits in REFE.