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Psychedelic Drugs and the Nature of Personality Change

LSD use may increase openness to experience even in regular users

Psychedelic drugs have been popularly referred to as “mind-expanding.” Some recent research suggests that psychedelic drugs, such as psilocybin and LSD, could actually affect personality traits, such as openness to experience, meaning that these substances may well be mind-expanding in this sense. One celebrated study found that drug-naïve volunteers who were given psilocybin experienced lasting increases in openness to experience that were evident more than a year later. An intriguing new study has also found that experienced LSD users reported short-term increases in openness to experience two weeks after an experimental dose of LSD. These studies raise some intriguing questions about the nature of the effects of such drugs on personality and the nature of personality change.

Courtesy of Theonlynewnumber via DeviantArt
Source: Courtesy of Theonlynewnumber via DeviantArt

Openness to experience refers to the breadth, depth and complexity of a person’s mental life. People high in openness to experience tend to be intellectually curious, artistically sensitive, interested in new experiences, and have an active imagination. In most people, openness to experience, like other personality traits, normally remains very stable over the long-term. However, there is also evidence that people experience momentary fluctuations on a day-to-day basis in states of mind related to personality traits (Schutte, Malouff, Segrera, Wolf, & Rodgers, 2003). For example, people may tend to feel more introverted in the morning and more extraverted in the evening, even though their general level of introversion/extraversion remains stable over the long-term. In a similar way, people might experience temporary changes in how open or closed they feel at a given moment, even though their general level of openness tends to remain more consistent over longer periods of time. Additionally, there is evidence that even fairly stable personality traits can sometimes change in response to major life events. For example, research suggests that some people experience increases in neuroticism in response to extremely traumatic life events (Ormel, Riese, & Rosmalen, 2012), such as an earthquake (Milojev, Osborne, & Sibley, 2014). Similarly, people might experience long and short term changes in openness to experience in response to certain triggering events.

As I discussed in a previous post, there is some evidence for a two-way relationship between openness to experience and the effects of psychedelic drugs. People with high levels of openness to experience are more prone to altered states of consciousness. More specifically, those who are high in the trait of absorption, which is closely related to openness to experience, have particularly strong responses to the mind-altering effects of psilocybin (Studerus, Gamma, Kometer, & Vollenweider, 2012). On the other hand, there was a study a few years ago that found that people who had never taken psychedelic drugs before underwent a sustained increase in openness to experience after taking a high dose of psilocybin, that was evident 14 months later (MacLean, Johnson, & Griffiths, 2011). Robin Carhart-Harris has proposed that psychedelic drugs may increase cognitive flexibility through their action on the serotonin system. He has suggested that psychedelics induce an ‘entropic state’ in which the mind/brain operates outside its usual optimal level of order in ‘a realm of relative disorder’ associated with ‘unconstrained cognition’ (Carhart-Harris et al., 2016) It is possible that psychedelic drugs may have a more or less lasting effect in this regard, that may account for their effects on openness traits, that are also related to cognitive flexibility.

A more recent study with experienced LSD users found that an experimental dose of LSD was associated with a small increase in openness to experience and in optimism two weeks later (Carhart-Harris, et al., 2016). Interestingly, users had no increase in delusional thinking during this period. This suggests that increases in openness to experience were not associated with impairments in users’ grasp on reality. This was a small study, which is limiting. Nevertheless, if the results of this study are more generally valid, they raise some intriguing questions about personality changes associated with psychedelic drugs.

I was particularly interested to note that even experienced users experienced a short-term increase in openness. Since it seems that psychedelic use can substantially increase this personality trait, one might expect that experienced users would eventually reach a maximal level of openness. However, it seems that even they have room to expand in this regard. One possibility, a very speculative one, is that in experienced users, levels of openness to experience fluctuate over time, waxing and waning in response to usage. That is, a user might reach a peak level of openness after a particular drug experience remaining at a plateau for a while, and then gradually subside to a somewhat lower level over time, but still remaining higher in this trait than most other people. Then the next time they take psychedelics they might reach a peak level of openness again, maintaining a sort of cycle of renewal. This possibility could be tested by asking users to track their levels of openness over time, to determine if fluctuations in this trait are related to their use of psychedelics.

If people who use LSD do experience personality change within as short a period as two weeks, this raises a question about how they know that they have changed and what this change consists of. One possibility is that short-term increases in openness are related to day-to-day mental states. As I noted before, people can experience day-to-day changes in their personality states, even though their general traits remain stable over time. Perhaps an intensely mind-altering experience like taking LSD is followed by a surge in highly open personality states in everyday life, such as increased feelings of awe, curiosity, and awareness of beauty, in the days and weeks following such an event. This might be what leads users to rate themselves higher in openness to experience after a recent LSD experience. With the passage of time, the demands of mundane life might take their toll leading to a reduction in the number and intensity of such states, leading to a return to a somewhat lower level of openness. In this view, changes in states produce trait-level change. An alternative possibility, is that psychedelics induce a more global change in how users feel about themselves, so that they feel like they are experiencing the world in a different way. In this view, a change in self-concept filters down to induce changes in personality states. This might explain why personality change can be so lasting and pervasive in some people, as in the psilocybin study. It is also possible that personality change might involve elements of both processes.

More in-depth studies on the effects of psychedelics such as LSD and psilocybin that investigated longer term changes in users’ states and traits could help deepen our understanding of what it means for personality to change and how people understand themselves when they rate their own personal characteristics.

© Scott McGreal. Please do not reproduce without permission. Brief excerpts may be quoted as long as a link to the original article is provided.

Image Credit

Blossuming Minds by Theonlynewnumber

Other posts about psychedelic drugs

Psilocybin and personality

Psilocybin and brain function

Psilocybin relieves anxiety and depression in the terminally ill

DMT, aliens and reality – part 1

DMT, aliens and reality – part 2

DMT: Gateway to Reality, Fantasy or What?

The Spirituality of Psychedelic Drug Users

Psilocybin Users Who Trip Without Drugs

LSD, Suggestibility and Personality Change

Can the Experience of Awe Open the Mind?


Carhart-Harris, R. L., Kaelen, M., Bolstridge, M., Williams, T. M., Williams, L. T., Underwood, R., . . . Nutt, D. J. (2016). The paradoxical psychological effects of lysergic acid diethylamide (LSD). Psychological Medicine, FirstView, 1-12. doi: doi:10.1017/S0033291715002901

MacLean, K. A., Johnson, M. W., & Griffiths, R. R. (2011). Mystical Experiences Occasioned by the Hallucinogen Psilocybin Lead to Increases in the Personality Domain of Openness. Journal of Psychopharmacology. doi: 10.1177/0269881111420188

Milojev, P., Osborne, D., & Sibley, C. G. (2014). Personality Resilience Following a Natural Disaster. Social Psychological and Personality Science, 5(7), 760-768. doi: 10.1177/1948550614528545

Ormel, J., Riese, H., & Rosmalen, J. G. M. (2012). Interpreting neuroticism scores across the adult life course: immutable or experience-dependent set points of negative affect? Clinical Psychology Review, 32(1), 71-79. doi:

Schutte, N. S., Malouff, J. M., Segrera, E., Wolf, A., & Rodgers, L. (2003). States reflecting the Big Five dimensions. Personality and Individual Differences, 34(4), 591-603. doi: 10.1016/s0191-8869(02)00031-4

Studerus, E., Gamma, A., Kometer, M., & Vollenweider, F. X. (2012). Prediction of Psilocybin Response in Healthy Volunteers. PLoS ONE, 7(2), e30800. doi: 10.1371/journal.pone.0030800

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