A psychedelic trip that leaves one person feeling transformed could leave another feeling unsettled — and personality may be part of the reason. In the Journal of Psychedelic Studies, researchers report that openness predicted positive, mystical experiences, while neuroticism was linked to more challenging and negative outcomes.
Psychedelic substances such as psilocybin (found in certain “magic” mushrooms), LSD, and DMT are known for producing profound alterations in perception, thought, and emotion. They act primarily on the brain’s serotonergic system and have been used in both ceremonial and experimental contexts for centuries. In recent years, scientific interest in these compounds has grown due to their potential to enhance well-being and treat mental health conditions, with some studies suggesting that a single experience can have lasting positive effects on quality of life.
The current study examined these experiences through the lens of the Big Five personality model — one of the most widely accepted frameworks in psychology. The Big Five describes personality across five broad dimensions: openness (curiosity and preference for novelty), conscientiousness (organization and reliability), extraversion (sociability and energy), agreeableness (cooperativeness and empathy), and neuroticism (tendency toward negative emotions).
While prior research has shown that psychedelic experiences can be deeply meaningful, people often respond in very different ways. Some find the experience transformative and life-enhancing; others encounter intense anxiety or distress. The study’s authors aimed to understand whether personality traits could help explain this variation. They also sought to assess both the quality of these experiences — whether they were mystical, challenging, or both — and their long-term consequences, whether positive or negative.
This individual differences perspective is often missing from psychedelic research, which tends to focus on average outcomes. By incorporating personality, the researchers hoped to provide a more nuanced picture of who might benefit most from psychedelic use and who might be more vulnerable to adverse effects.
“At Lund University, south Sweden, we have the national leading center of personality research, and applying individual differences in personality traits to one of the most phenomenologically interesting experiences a human being arguably can have is of course in the interest of psychological research. We also have several parallel projects, such as one of the first randomized controlled trials on anorexia and psilocybin, and the first doctoral project on psychedelic effects on adolescents compared to adults,” explained Petri J. Kajonius, an associate professor of personality psychology and assessment.
Because psychedelic use is prohibited in Sweden, the researchers recruited participants through an anonymous online survey shared on social media. The 400 respondents, one-third of whom were women, had an average age of about 34 years. Most had used LSD or psilocybin, and many reported taking these substances with a personal growth motive, often in natural settings and sometimes with a “trip sitter” present.
Participants were asked to recall the single most impactful psychedelic experience they had ever had, which typically occurred in their early twenties. They rated the significance of this experience compared to other life events, the degree to which it was challenging or mystical, and its lasting positive and negative effects. They also completed a 30-item questionnaire assessing their standing on the Big Five traits.
The researchers measured “challenging” qualities through reports of fear, difficulty, and threat during the experience, while “mystical” qualities were assessed through feelings of ego dissolution and a sense of unity. Positive and negative life consequences were gauged through changes in areas such as self-concept, relationships, anxiety, and mood.
The vast majority of participants rated their psychedelic experience as highly significant: 82% placed it among the top ten most meaningful events in their lives, 56% among the top five, and 11% as the single most significant.
Participants described their “most meaningful” psychedelic experience as both demanding and otherworldly. On the study’s 0–5 scales, the experience was rated moderately challenging (3.14) and even more mystical (3.63). Long-term fallout leaned strongly positive: negative aftereffects were minimal (0.14), while positive life changes were high (4.26).
Openness was the trait most consistently tied to beneficial outcomes. Higher openness related to stronger mystical qualities during the experience and to greater positive life effects afterward. When the sample was split at the mean, those high in openness had nearly double the odds of reporting substantial positive changes. Openness also showed a small link with reporting the experience as more challenging, suggesting that open individuals may engage more deeply and come away seeing more upside.
“The Big Five trait Openness seems to be a very strong predictor for many outcomes before, during, and after a psychedelic experience,” Kajonius told PsyPost. “This result is furthermore likely underestimated, seeing the low internal consistency in the psychometrics.”
Neuroticism showed the opposite trend. It was modestly associated with reporting negative consequences and with reporting fewer positive outcomes. Expressed as odds, higher neuroticism corresponded to a 56% increase in the likelihood of negative aftereffects. Although these effects were small, they suggest that people prone to anxiety and emotional volatility are more likely to experience lingering downsides and less likely to report broad, lasting benefits.
“The most important takeaway is perhaps that individuals do not see the world similarly, and that individual differences in Big Five traits is one avenue of exploring and understanding this fact,” Kajonius said. “Applying this to a psychedelic experience would, according to our hypothesis, yield some patterns from personality — which it arguably did indeed show.”
Other traits played a smaller role. Conscientiousness showed a modest positive association with beneficial life changes. Extraversion and agreeableness had only minor links with positive outcomes, and none of the traits related strongly to negative consequences beyond neuroticism’s modest effect.
The findings suggest that personality plays a meaningful role in how people experience and respond to psychedelics. For those exploring the therapeutic use of psychedelics, these insights could help tailor experiences to the individual, maximizing potential benefits while minimizing risks.
“Our study again gives evidence that not only dose and context matter, but also the person, the psychological constitution of the individual taking the psychedelic substance,” Kajonius told PsyPost. “This is of course well known within psychiatry, but for some reason this hasn’t been as evident in nascent research on psychedelics. For instance, neurotic persons should take extra caution, while open-minded persons tend to explore and grow in their personality in regard to psychedelics.”
As with all research, there are limitations to consider. The sample was self-selected, likely skewing toward individuals with especially meaningful or positive psychedelic experiences. As Kajonius noted, the sample “is very, very skewed towards psychonauts.”
Another complication is that psychedelic experiences themselves may alter personality traits, making it difficult to determine whether the traits influenced the experience or were shaped by it. Some research has suggested that psychedelic use can lead to lasting increases in openness and decreases in neuroticism.
Future studies could address these issues by using larger, more diverse samples, assessing personality before and after psychedelic use, and including people who have had less positive or more neutral experiences. Controlled experimental designs, though challenging with these substances, would also help clarify cause-and-effect relationships.
The study, “Big Five personality and the psychedelic experience: An initial report,” was authored by Petri J. Kajonius, David Sjöström, and Emma Claesdotter-Knutsson.
