People who regularly use psychedelic drugs outside of a clinical setting appear to process emotional information differently than non-users. A recent brain imaging study found that experienced psychedelic consumers process threatening facial expressions more efficiently and show altered neural responses to different emotions. The study was published in the journal Human Brain Mapping.
Classic psychedelics such as psilocybin mushrooms and lysergic acid diethylamide (LSD) profoundly alter sensory perception, mood, and self-awareness. Recent medical trials have shown that these substances may have long-term psychological effects. Patients who participate in these clinical trials often experience reduced symptoms of depression, less anxiety about terminal illness, and an increased ability to regulate their emotions. These clinical sites provide a safe, highly supervised environment with psychological support to guide patients through the intense acute drug experience.
The majority of psychedelic use around the world takes place outside of controlled laboratories. This naturalistic use involves varying doses, unpredictable environments, and differences in individual motivation. Because these different conditions can greatly impact the drug experience, the researchers wanted to see if the psychological benefits observed in rigorous clinical trials also applied to people who use psychedelics in the real world.
Paweł Orłowski, a researcher at the Brain Research Center at Jagiellonian University in Poland, led the study. Orłowski and colleagues Aleksandra Domagalik and Michał Bora aimed to map the brain activity of experienced users of psychedelic drugs to see how they respond to everyday emotional triggers compared to people who had never used drugs.
The researchers first surveyed more than 2,500 people. From this large group, we selected 33 experienced psychedelic users who reported taking psychedelic drugs at least 10 times in their lives. They paired this group with 34 non-users who expressed a desire to try psychedelics in the future.
To isolate the specific effects of psychedelics, the research team matched the two groups based on several demographic and lifestyle factors. Users and non-users were matched based on age, gender, education level, and size of city of origin. They were also matched on their history of meditation and use of other psychoactive substances, such as alcohol, cannabis, and stimulants. All participants were required to abstain from psychedelic use for at least 30 days prior to the experiment.
To observe how participants processed emotions, the researchers used functional magnetic resonance imaging. This technology measures blood flow in the brain and estimates which neural areas are most active at any given moment. Participants completed a facial expression recognition task inside a brain scanner.
During the task, participants observed a series of faces displaying angry, fearful, happy, or neutral expressions. Each image flashed on the screen for just a moment. Participants then used a button pad to accurately identify the emotion they had just seen as quickly as possible.
Behavioral data revealed significant differences between the two cohorts. Psychedelic users correctly identified angry facial expressions faster and with greater accuracy than psychedelic users. The two groups’ performance was surprisingly similar when it came to recognizing fearful, happy, or neutral faces.
The researchers interpreted this higher performance as a sign of increased efficiency in processing threat-related information. Often, encountering a threatening stimulus, such as an angry face, elicits a brief freezing response that slows cognitive responses. Regular psychedelic users seem to avoid this typical delay, process emotional information, and press the right buttons without hesitation or impulsive mistakes.
Brain scans confirmed these behavioral observations. When viewing angry faces, psychedelic users recorded decreased activation in brain regions associated with raw emotional responses and threat detection. These areas include the insular cortex and supplementary motor area, which are typically activated when a person responds to negative or alarming stimuli.
The opposite pattern emerged when participants saw happy faces. In response to positive emotional expressions, psychedelic users showed increased activity across various sensorimotor and parietal brain regions. These specific neural regions help process external sensory information and integrate bodily sensations, consistent with clinical reports of increased positive mood after psychedelic therapy.
The researchers also focused on the brain regions that make up the default mode network. This brain network is usually highly active when a person is resting, daydreaming, or contemplating their inner thoughts. An overactive default mode network is often associated with the repetitive negative thoughts seen in depressive disorders.
In specific regions of this network, non-users showed very distinct and diverse patterns of brain activation, depending on which specific emotion they were viewing. They spent a lot of cognitive effort processing negative emotions. In contrast, psychedelic users had much flatter and less differentiated neural responses across different emotional categories.
The authors suggest that this flattened response may fit into a concept known as predictive processing. This theory proposes that the brain constantly uses strict expectations based on past experience to navigate the world. These strong beliefs can force people into maladaptive defensive habits when they perceive a threat.
Psychedelics are thought to soften these rigid expectations. This relaxation causes the brain to rely more on the raw sensory data coming in through the eyes and ears, rather than filtering the world through rigid assumptions. By avoiding brute force mental filtering, psychedelic users may be able to process defensive triggers such as anger more smoothly and automatically.
One unexpected result involves the amygdala, a small structure deep in the brain that acts as an alarm system for fear and negative emotions. Previous clinical trials have often reported that psychedelic therapy calms amygdala reactivity for days or weeks after the administration session. However, this naturalistic study found that the difference in amygdala activation between users and non-users was not statistically significant.
Scientists have offered several explanations for this discrepancy. Because participants refrained from psychedelic drugs for at least a month before the scan, any biological sedative effects on the amygdala may be temporary and wear off within a few weeks. Alternatively, the specific type of brain scanning sequence used in the setup may not have been sensitive enough to capture subtle changes in such small and deep brain structures.
This study has several caveats that preclude definitive conclusions. Because this was a cross-sectional study that captured a single moment in time, it cannot prove that psychedelics caused changes in the brain. It’s still quite possible that people who are naturally gifted with a highly efficient style of emotional processing are simply more likely to seek out and stick with psychedelic substances.
This sample also comes with an inherent self-selection bias. By selecting participants who had used psychedelics at least 10 times, the researchers likely assembled a group of people who consistently enjoyed the drugs. Those who had early scary or unpleasant psychological experiences were likely to discontinue use and would not have participated in the study cohort.
Future investigations will need to follow people over long periods of time, from before they start using psychedelics to long after they have established naturalistic habits. Tracking brain scans over months or years could help scientists determine exactly how these powerful substances change emotional recognition in the real world.
The study, “Investigating emotional reactivity in experienced psychedelic users: a cross-sectional fMRI study,” was authored by Paweł Orłowski, Aleksandra Domagalik, and Michał Bola.
