The Relationship Between Personality and Sensitivity to Psychedelics

sensitive to psychedelics

When different people take the same dose of any psychedelic, some will have a more subjectively intense experience than others. This is due to dose-independent factors, or what many psychonauts, psychedelic enthusiasts, and researchers call set and setting. Set is your mindset going into the experience, whereas setting refers to all the environmental factors that can potentially colour the trip. While a person’s pre-existing mood and setting are seen to (and definitely do) play a significant role in the quality of the psychedelic experience, there is one undervalued aspect of set that can influence how intense someone’s journey might be: his or her personality.

Indeed, people intuitively feel that they are more sensitive to psychedelics than others. Even when considering all of the facets of set and setting, it seems that some individuals will have a more perceptually, emotionally, and spiritually intense experience than others – and that this is due to an underlying sensitivity to psychedelics. But where does this sensitivity come from? I will describe some perspectives from psychology that can help shed some light on this phenomenon, and further argue that anyone’s inherent sensitivity should be taken into account before deciding on a dosage.

Being Sensitive to Psychedelics Could Be Due to Your Personality

A fundamental reason why some individuals are more sensitive to psychedelics than others is that they are more sensitive people in general. In psychology, sensory processing sensitivity (SPS) is a heritable temperament/personality trait that refers to the tendency to process stimuli and information more strongly and deeply than others. 47% of the differences in people’s sensitivity are explained by genetic factors, with the rest (53%) shaped by life experiences and one’s environment. 

SPS includes sensory processing of aesthetic experiences, other people’s moods and feelings, loud noises, pain, hunger, bodily sensations, medications, caffeine, and other drugs (including psychedelics). In a 2016 paper published in Personality and Individual Differences, Sofie Boterberg and Petra Warreyn state that SPS “reflects an increased sensitivity of the central nervous system”.  The nervous system is hyper-excitable, in other words.

Synonyms for SPS include hypersensitivity or high sensitivity while an individual who has the trait is known as a highly sensitive person (HSP). The American psychologist Elaine Aron, who coined the term HSP in 1996, has stated that the trait SPS can be found in 15 to 20% of the population. HSPs are believed to be easily overstimulated by external stimuli because they have a lower sensory threshold. This means that their nervous system is varied in such a way that it takes a weaker stimulus to generate a response than a less sensitive person. HSPs will be quick to notice – and react to – stimuli, they react strongly to more types of stimuli compared to non-HSPs, and they react more strongly to stimuli overall. They simply notice sensory stimuli more easily. This would include, for instance, being more bothered by intense and chaotic stimuli, such as loud noises and crowds.

We can see from brain imaging studies that SPS is associated with differences in brain activity when information is being processed by an individual. HSP scores are associated with stronger activation of brain regions involved in awareness, empathy, and action planning. There is also evidence that high SPS is associated with genes that affect the activity of neurotransmitters like serotonin, dopamine, and norepinephrine.

The trait SPS has been observed in more than 100 nonhuman species. SPS is not a disorder, although it does increase an individual’s risk of experiencing high stress, being easily overwhelmed, sleep problems, depression, anxiety, and other mental illnesses; having a generally high sensitivity means, of course, that you will respond more strongly not just to positive stimuli but to negative stimuli as well. Aron has sought to clarify that high SPS is not the same as similar-appearing traits or disorders, such as shyness, sensation-seeking, sensory processing disorder, and autism. SPS is linked to brain differences that are not seen with these other conditions, including autism spectrum disorder (ASD), schizophrenia, and post-traumatic stress disorder (PTSD). Moreover, both introverts and extroverts can be HSPs. 

SPS is an innate survival strategy and, like all with survival strategies, it has its advantages and disadvantages. SPS persists as an inheritable personality trait and nervous system variation because it can have adaptive value, even if, in some individuals, a condition like depression develops or is more likely to be chronic and severe. It’s important to keep in mind that no survival strategy, evolutionarily speaking, can be perfect; there will always be trade-offs. Furthermore, these survival strategies, such as being more sensitive to your internal and external world, are concerned with gaining advantages that allow you to survive longer or mate more often, so you can pass on your genes, not so you can be a happier person. HSPs, while they are at additional risk for psychological distress, are, nonetheless, psychologically primed to form deep social bonds, as well as be more attuned to the external world, which is useful for avoiding threats, obtaining resources, and adapting to environmental circumstances.

Amongst both humans and members of other species, individuals who differ in their responsiveness to stimuli coexist, with variations having different evolutionary costs and benefits. So being an HSP is normal and nothing to feel ashamed about; it is not a defect, weakness, or character flaw. And while it may, indeed, feel like both a blessing and a curse, it is a trait that must be understood, accepted, and taken into consideration when navigating one’s environment, emotional life, and relationships. It is not a trait that should be denied, ignored, rejected, hated, or medicated. High sensitivity should be valued and appreciated, as this trait can greatly enhance one’s capacity for creativity and empathy; plus HSPs tend to have a rich and complex inner life and are often deeply moved by the arts and music.

Taking all of this into account, when people claim they are sensitive to psychedelics, they may, in fact, be HSPs. Often, people who are sensitive to psychedelics display high sensitivity in other respects, such as being more sensitive to other psychoactive drugs, medication, caffeine, as well as the situational, social, and emotional dimensions of life.

When you are highly sensitive and you take, say, a moderate dose of a psychedelic, the same dose as a fellow tripper, it is very possible that your experience will be more intense than their’s, and not just because of individual differences related to your pre-tripping intentions, expectations, thoughts, feelings, life situation, history, attitudes, worldview, beliefs, mental health issues, or other personality traits. All of these myriad factors are relevant, but so is the influence of innate sensitivity. Those who are less sensitive to psychedelics may (excluding the factor of tolerance) have a higher sensory threshold than others, and so find that they need to take larger doses to achieve desired effects.

Some psychedelic users may be surprised about how they can take a dose of a psychedelic that results in such a sensorily and emotionally rich experience, which, for others, may feel underwhelming. Being sensitive to psychedelics, like being highly sensitive in general, has its advantages and disadvantages. It is true that HSPs may not need to take as high a dose as others (giving them more bang for their buck), or that they are prone to have deep psychedelic experiences, but the flipside of this is that there is perhaps a greater chance of being overwhelmed and reacting more strongly, in a negative way, to other people (including what they say and their non-verbal cues) and one’s environment (including how it changes during the trip). 

The Need to Take Sensitivity to Psychedelics Into Account

Given that being sensitive to psychedelics can alter the intensity of a trip, it seems that this should be taken into account when these compounds are taken, whatever the context, be that in a clinical trial, at a clinic or retreat, or amongst individuals taking psychedelics in a setting of their choosing. 

In clinical trials with psychedelics, differences in body weight are sometimes used to adjust the dosages given to participants. And psychedelic users often mention their body weight when publishing trip reports, considering this to be a relevant factor in how intense their experience was relative to their dose. However, researchers who have compared psilocybin studies including weight-adjusted groups and fixed-dose groups found “no evidence that body weight affected subjective effects of psilocybin.”

I would be interested to see, though, trials whereby scores of SPS lead to adjusted doses compared to trials involving fixed-dose groups and to find out if high sensitivity does influence the subjective effects of a psychedelic experience and, if so, to what degree. I would not be surprised to see a relationship. (It should be stressed that personality is not necessarily the only or even the most crucial factor when it comes to people’s differing reactions to psychedelics. Individual differences in genetics and the brain could play a role too, as there are genes that influence the activity of serotonin 5-HT2A receptors, which are what the classic psychedelics bind to and which mediate the resulting psychoactive effects.)

If sensitivity to psychedelics is a significant factor influencing the intensity and subjective effects of a trip, it isn’t just clinical trials that should be interested in taking this into account, but clinics and retreats, too. This would be useful for several reasons, with one major reason being harm reduction. If you give all depressed clients at a future psilocybin clinic the same dosage, without taking into account sensitivity, and some of these clients are HSPs (which is likely, given how sensitivity is connected to depression), then some individuals may have especially strong trips. This doesn’t mean, necessarily, the experience will be overwhelming, but there is an increased chance of this when someone trips harder than they need to. This is why people in clinical trials are given doses that are typically high enough to induce a mystical experience but they are not unnecessarily high. HSPs, nonetheless, might be able to reach states of ego dissolution, unity, and transcendence from a dose that would certainly cause a non-HSP to trip but perhaps not lose their sense of personal identity.

Finally, for anyone thinking of taking a psychedelic, it’s best to have as much self-awareness as possible before going into the experience; and this includes having an understanding of whether or not you’re an HSP. Signs of high sensitivity have already been alluded to. You can see the clues of it if you have tendencies like becoming easily overwhelmed or overstimulated, needing to withdraw from stimulation, being easily startled, taking things personally, absorbing other people’s emotions, being very sensitive to animal suffering, taking longer than most to make decisions, becoming irritable when hungry, having a hard time faking an interest in topics, feeling engaged when having deep and meaningful conversations, and being aversive to small talk. 

If you come to understand yourself as an HSP, you may find you really don’t need to take the same doses of psychedelics as others to reach the level of intensity you’re aiming for. On the other hand, if you lack this understanding and take what is considered by many to be a low or moderate dose of a psychedelic, some of the resulting subjective effects may be unexpected. HSPs should also be cautious when thinking about taking higher doses: this means paying close attention to set and setting, as well as making sure that support is available should things become overwhelming or distressing.

Being sensitive to psychedelics is something considered and taken into account by many psychedelic users, yet it is an area that deserves more research. This will benefit both our understanding of how psychedelics affect individuals differently and our subsequent ability to administer and take these compounds with the utmost care.


  1. xerxes
    February 28, 2022 / 10:50 pm

    Psilocybin has taught me that brain/body chemistries differ widely, irrespective of personality traits or body mass. I have a sensitive personality type, loads of depressive illness, and a low body weight — but even large doses of psilocybin typically have negligible psychedelic effects on me (an MAOI adjunct being virtually mandatory even to approach threshold effects). Nutrition (and the state of one’s gut microbiome) play a role in the production of dopamine and serotonin, both implicated in the psychedelic experience. Based on my own (comparative) experiences, I would agree that “one size fits all” does not apply to psilocybin dosage.

    • Sam Woolfe
      March 1, 2022 / 9:39 am

      I can imagine that individual differences in brain/body chemistry, as well as nutrition, could play a role as well. I did try to find out if genetic/brain differences could explain people’s differing levels of sensitivity to psychedelics, but I didn’t find anything conclusive. For instance, a company has developed a genetic test kit so you can find out your sensitivity to psychedelics, but there are some issues with it. In an article about this, Shayla Love writes:

      “The test said that a gene variation that led to a higher density of these [5HTR2A] receptors would make a person more sensitive to psychedelics. The suggestion here is that a higher density of these receptors is correlated with the quality of the trip that they’re going to have.

      Charles Nichols, a professor of pharmacology at LSU School of Medicine who researches serotonin receptors, put it plainly: “This really means nothing,” Nichols said. “The premise of trying to link one polymorphism with a behavioral predictor is just, I would say, preposterous.”

      There are many other gene variations that could influence serotonin receptors outside of density, Nichols said. “It may not be the amount of serotonin receptors that you have to look at; it might be the function of the serotonin receptor: How is it signaling? How is it desensitizing?”

      It doesn’t mean that these receptors are unimportant. HaluGen cites 55 references on its website, and Nichols pointed out one to me: a 2019 paper from the journal Nature that showed that psychedelic effects emerge through serotonin 2A receptors. They reported that the intensity of psychedelic effects, as reported by their participants, was related to the receptor occupancy—meaning how many receptors were stimulated by psilocybin’s active metabolite, psilocin.

      Nichols said this was significant research; the study showed without a doubt that these specific serotonin receptors are relevant to psychedelic intensity. But the exact relationship between gene variations, receptor density, and receptor occupancy still needs more research.”

  2. J
    March 9, 2022 / 6:30 pm

    I’m really sensitive to psychedelics, and I see the same thing with my brother and cousins. Even marijuana, which isn’t exactly a psychedelic, affects me harder than my friends. I can’t smoke weed around people, it’s just too intense. I can’t speak, have a conversation, nor concentrate but I feel my body and mood times 10 when I’m high. My cousin sometimes goes into almost “trance” like states which is actually embarrassing, that’s we tend not to smoke with others. And it’s not just a factor of tolerance, I’ve been through phases where I smoked for days on end and I eventually do build up some tolerance but it takes longer compared to my friends. They always say I’m lucky haha, but I’d much rather have their fun, relaxing experiences with marijuana. I’ve only done shrooms once, I did a little more than a gram and I have no idea what happened. I don’t know if I perhaps fell asleep at one point on shrooms, but I forgot that I had a physical body. I don’t know if that counts as an “ego death” because I did have a moment of “coming back” and remembering that I existed in the world. It was very insightful, but very intense, almost maddening. I’d do it again, but I definitely have to work my way up to it and prepare mentally beforehand.
    Thanks for this article, I never realised that this was actually a thing.

  3. Daniel
    July 3, 2022 / 11:23 pm

    I feel that I am an HPS (haven’t measured SPS officially) and have found myself extremely sensitive to substances in general- alcohol, marijuana, and psychedelics in particular. It was the after effects of psychedelics that in part led to the realization that I am highly sensitive. My trip was extremely overwhelming- I felt infinitely vulnerable, helpless, and traumatized. It was a feeling I hadn’t felt until early childhood, when my mother put me in similar situations where I felt confused, helpless, and scared. It was quite a difficult experience, which I’m grateful to have made through.

    With that being said, I have felt more sensitive for months after use. I feel more easily overwhelmed by memories of childhood adversity and work stress, and have felt more dependent on my girlfriend. I am convinced that this is related causally to the psychedelic use, although my rational mind tells me that this will go away in time. I am hopeful that the deeper purpose of this experience is to make me understand that I am highly sensitive, and thus give me an avenue to understand more about who I am and how I can improve myself.

    • Sam Woolfe
      July 4, 2022 / 11:06 am

      It sounds like the experience was pretty challenging, but if it leads to more self-understanding and self-acceptance, then that’s a very positive and valuable thing.

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