Psychedelics and Apeirophobia: Can Altered States Evoke a Fear of Eternity

While one of the main recognised benefits of psychedelics has been a lessening or elimination of the fear of death (particularly in those with a terminal illness), this effect is not universal. Indeed, a 2025 study published in the journal Death Studies found that many people experience an increase in death anxiety after psychedelics. This possible effect (risk?) of psychedelics is rarely (if ever) mentioned or discussed. But it should be, given that, in that 2025 study, out of 155 participants, 57 reported this increase in death anxiety. That’s hardly an insignificant number: it’s a third of all those surveyed (in this study at least). And for clarity, 17 participants reported no change; that is, they had scored the same in their intensity of death anxiety pre- and post-study. 

This study echoed the findings of 2023 research by Moreton et al., also published in Death Studies, which, similarly, found that a non-substantial proportion of those surveyed (16.9%) experienced an increase in death anxiety following psychedelic experiences. (In the 2023 study, only 3.98% of people reported no change in their levels of death anxiety.) The researchers of the 2025 study state, “More research is needed into factors that might drive the direction of the effect of psychedelics on death anxiety.”

We have an idea of some of the factors that seem to mediate decreases in death anxiety: some research indicates it’s metaphysical belief change, such as belief in panpsychism (as the 2025 study highlights) or belief in the afterlife and a supreme being, whereas another study pinpoints increased impermanence acceptance as the strongest predictor (more so than metaphysical beliefs); this refers to the emotional acceptance of one’s temporary existence.

Might this give us a clue as to why some people experience an increase in their fear of death after psychedelics? While research is scant in this area, I’d like to explore some plausible candidates for factors that influence increases in death anxiety, particularly a type of death anxiety I’ve become interested in more recently, as it’s one I’ve felt from time to time: the experience of apeirophobia (the fear of an eternal afterlife), which I wrote about here.

Before getting to apeirophobia, however, let’s take a look at non-apeirophobic ways psychedelics could increase the fear of death, as it’s important to note that apeirophobia is not the only way this could happen (and it may be an uncommon way in which psychedelic users experience greater fear of death than they did prior to psychedelics).

If belief in panpsychism or the supernatural predicts decreases in death anxiety, then perhaps belief in materialism or physicalism (reality is ultimately material or physical, which includes a rejection of belief in the soul, the afterlife, or a deity) predicts increases in this form of existential dread. Not everyone is distressed by the acceptance of materialism or physicalism, of course; for instance, in the study on impermanence acceptance, the researchers note that this benefit applied to materialists. Those who believe in materialism can feel at peace with their mortality due to an increase in impermanence acceptance. Many people who reject the supernatural come to emotionally embrace the fact of their finitude.

However, it is also possible for materialism to engender a dread of the fact that one's life has an expiration date. I can actually remember the first time this fact dawned on me, during an English class at sixth form (so I must’ve been around 16/17). I can’t remember if there was a reason the topic was on my mind (maybe it was related to the book being discussed), but I suddenly had the realisation that when I die, it’s as if the whole world ends – if my experience of the world is dependent on my life, and my life will end at some point, then so will my experience of the world. So, while I can imagine the world continuing on, it won’t in my own subjective experience. This was a somewhat terrifying realisation – to know that everything (as I knew it) would eventually disappear. 

If psychedelics can generate all sorts of insights, perhaps this kind of insight could also occur. A visceral acceptance of materialism could lead one to become terrified at the prospect of all experience ending, and there being nothing to prevent it. One might consider this to be how things are, on psychedelics, if one, through introspection or altered perception, perceives all things as made of ultimately made of matter. One could reject the concept of the soul or the afterlife – if one already believed in these concepts or entertained them – and instead view death as the ultimate end. The end of the road.

The adoption or intensification of belief in materialism could easily turn into impermanence rejection, an anxiety about one’s impermanence. After all, it’s one thing to abstractly accept the fact of death; it’s another thing to emotionally accept it. Since psychedelics often work with what lies unconscious (e.g. our fears), it’s possible that materialists, even hardened materialists, may be confronted with their fear of death, which they had only ostensibly embraced. In this way, psychedelics could trigger a disturbing, heightened awareness of one’s impermanence, as well as a disillusionment with ‘comforting narratives’ intended to soothe this anxiety.

Psychedelics lead many people to embrace the idea of an afterlife, sometimes a religious type of afterlife, but oftentimes, a non-religious notion (e.g. being unified with ‘the divine’, reunited with loved ones, or existing in some eternally blissful realm). This often happens because one feels like they witness or enter this reality on psychedelics – many people experience becoming detached from their body (or losing awareness of having a body or being a human) and existing in a state of timeless awareness or becoming Divine or Cosmic Consciousness (the sum of all things).

This can feel like Ultimate Reality – and the reality that awaits one after death. One’s physical existence feels less real or illusory in comparison. And since the experience of this Ultimate Reality is often felt as euphoric or blissful – this is the ‘deeply felt positive mood’ aspect of mystical experiences – death is no longer feared. Like many of those who subscribe to religious traditions, many psychonauts welcome what awaits them after death with open arms. They know, deep down, that something better is in store.

On the other hand, not everyone embraces the idea of an afterlife – of existing forever after death. This can, instead, instil an overwhelming feeling of anxiety, dread, and panic. And I find this completely understandable: I don’t personally want to go on existing forever, without the option of choosing this reality or not, or, when I do enter the reality, lacking the option to leave it if I get supremely bored, fed up, distressed, and so on. 

In short, psychedelics can evoke apeirophobia if one becomes convinced of an eternal afterlife and is fearful of this prospect. Indeed, the experience of timelessness on psychedelics is not always blissful.

I think there are different ways in which psychedelic-inspired apeirophobia can manifest. For example, Jules Evans is interested in the experience of ‘cosmic loneliness’ in challenging psychedelic experiences. He writes:

One of the tarot cards you can draw in mystical / psychedelic experiences is a feeling of absolute, existential, cosmic separation and loneliness. It’s truly horrible, if you’ve ever experienced it, and can leave people seriously traumatized for weeks / months / years. It’s like the polar opposite of the feeling of blissful union with the All. People wonder - is this the cosmic truth of the human condition, is this what is real? Perhaps all suffering emerges from a feeling of separation, disconnection and loneliness - if so, this is extreme suffering, even a sort of hell experience. But people come back from it, thankfully. Anyway, here are some accounts of this experience from Reddit.

Another type of apeirophobia I had relates to DMT. It is common for many people on DMT to have the experience of ‘leaving the simulation’ (i.e. leaving the simulation that is consensus reality and being absorbed into the more ultimate reality: the DMT realm). This may help many with the fear of death, especially if their experience of the DMT realm was positive – full of love, light, warmth, and caring entities. However, I can imagine not everyone would be thrilled about being thrust into the DMT realm after death, and for that just to be one’s existence from then on, forever. As blissful, mindblowing, fascinating, and entertaining as DMT experiences can be, the idea of eternally being in a space with everything moving and changing a mile a minute, with strange entities interacting with me, doesn’t sound that appealing. I think that would quite quickly become overwhelming.

The extended DMT state – lasting around 20 minutes, instead of 10 – has been well-tolerated by volunteers (with no increases in anxiety or massive spikes in heart rate), but I imagine this picture would be very different if DMT experiences lasted hours, days, months, or years: imagining a DMT experience lasting years sounds like torture, and years are nothing in relation to eternity.

While I haven’t personally come across accounts of DMT users who’ve experienced apeirophobia as a result of their DMT use, I would be curious if belief in a DMT-like afterlife does have this effect for some users. Yet, regardless of the kind of apeirophobia induced by psychedelics, research on this link does not exist, so I’d welcome research and discussion in this area to see if, and to what extent, this is a potential risk of psychedelic use.