Mindfulness regularly induces altered states of consciousness

Mindfulness, or the act of being attentive to the present moment, is gaining more and more prominence as a way of managing poor mental health. Fifteen percent of adults in the UK have tried some form of mindfulness, and many NHS trusts recommend the practice to patients experiencing distress. Yet despite its reputation as a way of dealing with anxiety, you may not always end up feeling calmer after engaging in mindfulness.

Like other practices such as sensory deprivation or hypnosis, mindfulness can disrupt our usual conscious experience — inducing dissociation, changes in one's senses, intense emotions, or impaired cognition, for example. Writing in PLoS One, Julieta Galante, Jesús Montero-Marín and team explore such changes in consciousness, finding both a lasting impact of mindfulness and suggesting ways that practitioners can protect themselves from harm.

Participants in this randomised control trial were 616 students at the University of Cambridge, none of whom were currently suffering from severe periods of anxiety, depression, hypomania, or psychotic episodes. Some participants took part in a mindfulness condition, attending a weekly, 90-minute long mindfulness skills session, and were encouraged to practice mindfulness at home. Others engaged in their usual mental health support with no additional mindfulness practice.

The team also collected information on students' psychological distress both before the programme and one year after its completion, data on their meditation practices, and whether or not they had continued to engage in mindfulness in the year since their course had completed.

Finally, the team looked at altered states of consciousness. Here, students were presented with examples of altered states of consciousness (e.g. "it seemed to me that my environment and I were one") and asked to rate how much this applied to their experiences on a scale from 1 to 100. Any experience potentially induced by drugs or alcohol was discounted.

The results indicated that mindfulness practice can indeed cause altered states of consciousness; and the more mindfulness you engage, in the more likely such a state is to occur.

For example 'unity', or the "sense that borders dissolve and everything... is perceived in an integrated way", occurred at double the frequency and higher intensity in those who meditated, both in informal and formal practice. There was also a more than doubled frequency of disembodiment, or feeling of separation from the body, in the group who engaged in mindfulness compared to controls. A substantial proportion of these two experiences (43% of unity experiences and 29% of disembodiment) occurred during meditation itself.

There was also evidence of a link between mindfulness and a sense of bliss and insightfulness, adding to research that suggests meditative practices can induce spiritual or mystical experiences, though this was slightly weaker. The team also suggests that the correlation here might be because those who experience mystical feelings are more likely, in turn, to engage in meditation, rather than meditation per se causing such experiences. There was also weak evidence that engaging in mindfulness increased audio-visual synaesthetic experiences.

The team has a number of suggestions as to why mindfulness practice can increase the incidence of altered states of consciousness. One is that meditation can increase decentering of the self, thus leading to disembodiment; another is that altered states of consciousness happen all the time, but that mindfulness provides people with the self-reflective tools to recognise them. "Mindfulness may make such experiences more salient and meaningful, such that memories of those experiences were more readily available," the team writes.

Altered states of consciousness may be accompanied by feelings of bliss, as reported by some of the participants in this study. For others, however, the feelings that arise may be unpleasant or problematic, particularly in those prone to anxiety or other forms of distress. At its most extreme, for example, disembodiment can be experienced as a sense of dissociation. Similarly, research has already found that mindfulness can induce flashbacks in those with PTSD. Equipping people with the knowledge that altered states may occur could therefore be the difference between a positive and negative experience with mindfulness.

Read the paper in full:

Galante, J., Jesús Montero-Marín, Vainre, M., Dufour, G., García-Campayo, J., & Jones, P. B. (2024). Altered states of consciousness caused by a mindfulness-based programme up to a year later: Results from a randomised controlled trial. PLoS ONE, 19(7). https://doi.org/10.1371/journal.pone.0305928