Mindfulness in clinical psychology and personal practice: do we know enough about the potential side effects of this cognitive intervention?

Author's Note (2026): This article was originally published in September 2016 in Psych-Talk, the British Psychological Society's quarterly student publication. At the time, I was serving as editor while studying cognitive neuroscience at Birkbeck College, University of London. Systematic research into meditation-related adverse effects was sparse, and my motivation was to raise this topic when mindfulness was being largely uncritically accepted as a benign approach in cognitive therapeutic interventions. Just eight months after publication, Lindahl et al. would publish their landmark study documenting 59 categories of meditation-related challenges, followed by the development of formal MRAE (meditation-related adverse effects) measurement tools. This article represents an early student voice raising concerns that would soon become a significant research focus.

Preface (2026)

I became concerned that mindfulness cognitive techniques could actually lead to negative mental health issues, particularly for diligent, regular practitioners. My personal experience included symptoms of disembodiment, depersonalisation, and derealisation, which thankfully eventually resolved after ceasing the practice. I discovered that my experiences mirrored known "dark night" effects of long-term traditional Buddhist meditation that would later be formally recognised as meditation-related adverse effects (MRAEs).

During the two or three years leading up to my experiences, I had also been exploring, with some seriousness, Buddhist spirituality and practices. From a spiritual perspective, I was looking for answers to the difficult questions we all face about why we are here and the deeper realities of life. My intention had been to develop my studies toward a research theme that explored the potential benefits of meditation as a practice in cognitive therapy, as well as to shed light on the neurological functions that are engaged and any emergent neuroplastic effects.

Since this article was written, extensive research has validated many of these concerns. Studies now show that 25–87% of meditators report adverse effects, with 3–37% experiencing functional impairment (Lindahl et al., 2017; Britton et al., 2021; Goldberg et al., 2022). The symptoms I described—depersonalisation, derealisation, and disembodiment—are now recognised as key risk factors associated with lasting negative outcomes.

Research has confirmed that dissociation symptoms, while less frequent than anxiety or sleep disturbances, carry a 5–10 times greater risk for lasting negative effects requiring intervention (Britton et al., 2021). What I experienced as a postgraduate student in 2014–15 is now understood to be part of a broader pattern that affects a significant minority of practitioners, particularly those with certain vulnerability factors such as childhood trauma or intensive practice patterns (Lindahl et al., 2017; Goldberg et al., 2022).

The spiritual dimension of my experiences deserves some mention. We are in a time when there is an accelerating trend towards explaining the spiritual with the scientific, of which I myself was clearly a proponent at that time. However, after my derealisation symptoms I began to question whether, in the context of Buddhist thought, the effect seemed not to be a negative digression but actually a positively pursued stage of spiritual development—a breakthrough towards Satori or enlightenment. Research has since confirmed that Buddhist frameworks do normalise experiences of psychological distress, reframing them as necessary stages of the contemplative path (Lindahl et al., 2020). So, a feature, rather than a 'bug'.

I ultimately rejected the idea that emptying the mind of self-awareness is an empirically good objective. I also turned away from the notion that there is a 'special' state of mind or knowledge that a human being can attain, which is a foundational idea of Buddhism, as well as other religious philosophies such as Gnosticism, humanism, and New Age thought. The next step after derealisation, which is difficult to describe but is very unpleasant and accompanied by extreme demotivation, a sense of separation, and loneliness, was not one I wanted to encounter. Tibetan Buddhist writings have described it as the 'pit of the void'—which is certainly apt.

Shortly after my rejection of Buddhism and while recovering from my experience with mindfulness techniques, my life took an unexpected turn. I was asked very pointedly one day in class by another student if I was an atheist. The question seemed to come out of nowhere and I found that I could not agree that I was. I viscerally rejected it internally although I said very little at the time. This reaction surprised me. I subsequently decided to read the Bible, from cover to cover, with the usual thorough approach I would apply to any unfamiliar topic.

I found the truth I had been long seeking turned out to be on the first line of the first page of the first chapter: 'In the beginning God created the heaven and the earth'. What if that was true? It changes everything. It made me responsible to my creator. It meant that everything that followed in the Bible is also true. In this way, God entered my life, and within a few months of reading and praying I became a Christian, with saving faith in the Lord Jesus Christ. I attribute my recovery from symptoms of depersonalisation and derealisation to prayer during that time.

If the following article was prescient, I thank God for that, and I am happy that it has been followed up with the systematic, serious research I had hoped for. I hope that it will be useful to others who may have experienced similar adverse effects as a result of mindfulness meditation, or to clinicians who have come to question mindfulness as a cognitive intervention in the context of their practice.

Mindfulness in clinical psychology and personal practice: do we know enough about the potential side effects of this cognitive intervention?

Since the 1970s, Buddhist meditation practices, typically in forms known as "mindfulness", have become widely adopted into the array of clinical psychotherapeutic treatments available for psychological distress, such as anxiety and depression, offered in private and public health settings (Keng, Smoski & Robins, 2013). From a therapeutic perspective, mindfulness meditation has been described as deliberate self-training to cultivate an accepting awareness of the flow of thoughts and sensation in the present moment (Sedlmeier et al., 2012). In the context of Buddhist spirituality, meditation has the particular objectives of transcending suffering and achievement of an enlightened state (Harvey, 1990).

Mindfulness techniques, including Mindfulness Based Stress Reduction (MBSR) (Kabat-Zinn, 2003) and Mindfulness Based Cognitive Therapy (MBCT) (Teasdale, Segal & Williams, 1995) involve a programme of introspective practices based on awareness placed on the movement of the breath or similar meta-awareness of a bio-physiological activity. Mindfulness techniques have also become a popular self-help approach, widely practiced outside of supervised clinical settings, and have become associated with the notion that anything can be done "mindfully" (Purser & Loy, 2013).

In a sense this is true, but it is not necessarily a universally beneficial concept. Notably, the Buddhist tradition acknowledges both "right" and "wrong" (Purser & Loy, 2013) or skilful or unskilful, application of mindful attention. Avoiding the misdirection of mindfulness toward wrong action or unhelpful behaviour is embedded in traditional Buddhist practice and supervised training, where the potential pitfalls of meditation have been long understood (Sharf, 2015). This underlines an implicit disconnect in the therapeutic extraction of mindfulness from origins embedded within the complex ethical and philosophical frameworks of various traditions, such as Zen or Theravada (Sharf, 2015). Within Buddhism, mindfulness integrates with an ethical model; working within the five ethical precepts, for example, is viewed as pivotal to dissolving fear (Manjusura, 2004).

A range of unwanted consequences of mindfulness practice have been reported, including sleep disturbances, increased anxiety and panic attacks. Relaxation induced anxiety is a known condition that may potentially be triggered in this way (Heide & Borkovec, 1984). Foster (2016), reporting on the experiences of a participant on a corporate mindfulness course, describes the participant's symptoms of acute panic and subsequent psychotic breakdown lasting over 4 years, having onset during her mindfulness course. Negative experiences, although not always severe, seem relatively common according to Shapiro's research (1992) and as emerging from the work of Farias and Wikholm (2015).

Well known in Buddhist circles, are experiences described as the "dark side" of enlightenment (Lofthouse, 2014), also known as falling into "the pit of the void" (Young, 2009). This phenomenon is described by practitioners, including novices, variously as feelings of loss of identity, intrusive negative thoughts, disembodiment and a loss of pleasure in everyday activities (Rocha, 2014). After initial feelings of calm expansiveness and positive affect, I can report going on to experience a significant sense of depersonalisation and separation from my normal embodied sense of self and feeling isolated from social interaction, after two months of a regular meditation practice.

Mindfulness meditation has been called the "Buddha Pill" (Farias & Wikholm, 2015) and there is now, arguably, a need to study it in a similar way to pharmaceutical treatment. There is a call for further randomised and controlled trial based research into short and long-term psychological and neurocognitive effects, as distinct from the therapeutically driven study that has dominated the field to date (Sedlmeier et al., 2012).

It is not yet clear how much or how little MBSR, for example, might be needed to produce chemical and plastic structural changes in the brain (Hölzel et al., 2011), which may manifest in alterations in behaviour and/or perceptions of the self and everyday reality. Can meditation change you (Farias & Wikholm, 2015)? Yes, it evidently can and this may include desirable feelings of calmness and detachment, as evidenced as having therapeutic benefits for people with depression and anxiety (Keng, Smoski & Robins, 2013). However, questions remain concerning detrimental outcomes: do we now need a more scientifically informed understanding of unwanted psychological side effects and individual suitability for mindfulness as "medication"?

Originally published in Psych-Talk, September 2016. © British Psychological Society. Reproduced with permission under author retained rights.

References

Keng, S.-L., Smoski, M. J., & Robins, C. J. (2013). Effects of Mindfulness on Psychological Health: A Review of Empirical Studies. Clinical Psychology Reviews, 31(6), 1041–1056.

Kabat-Zinn J. (2003). Mindfulness-based interventions in context: Past, present, and future. American Psychological Association, 10(2), 146–156.

Farias, M. & Wikholm, C. (2015). The Buddha Pill: Can meditation change you? London: Watkins Publishers.

Foster, D. (2016). Is mindfulness making Us Ill?, The Guardian, retrieved 6 June 2016 from http://www.theguardian.com/lifeandstyle/2016/jan/23/is-mindfulness-making-us-ill

Harvey, P. (1990). An Introduction to Buddhism: Teachings, History and Practices, Cambridge: Cambridge University Press.

Heide, F. J., & Borkovec, T. D. (1984). Relaxation-induced anxiety: Mechanisms and theoretical implications. Behaviour Research and Therapy, 22(1), 1–12.

Hölzel, B. K., Carmody, J., Vangel, M., Congleton, C., Yerramsetti, S. M., Gard, T., & Lazar, S. W. (2011). Mindfulness practice leads to increases in regional brain gray matter density. Psychiatry Research – Neuroimaging, 191(1), 36-43.

Lofthouse, G., (2014). Enlightenment's Evil Twin, retrieved 6 June 2016 from http://www.theatlantic.com/health/archive/2014/12/enlightenments-evil-twin/383726/

Manjusura (compiler) (2004), Dhammpada, The Voice of the Buddha, London: Naxos Audiobooks.

Purser, R. & Loy, D. (2013). Beyond McMindfulness, Huffington Post, retrieved 6 June 2016 from http://www.huffingtonpost.com/ron-purser/beyond-mcmindfulness_b_3519289.html

Rocha, T. (2014). The Dark Knight of the Soul, retrieved 6 June 2016 from http://www.theatlantic.com/health/archive/2014/06/the-dark-knight-of-the-souls/372766/

Sedlmeier, P., Eberth, J., Schwarz, M., Zimmermann, D., Haarig, F., Jaeger, S., & Kunze, S. (2012). The psychological effects of meditation: A meta-analysis. Psychological Bulletin, 138(6), 1139–1171.

Shapiro, D.H. (1992). Adverse effects of meditation: a preliminary investigation of long-term meditators, International Journal of Psychosomatics, 39, 62-67.

Sharf, R. H. (2015). Is mindfulness Buddhist? (and why it matters). Transcultural Psychiatry, 52(4), 470–484.

Teasdale, J. D., Segal, Z., & Williams, J. M. G. (1995). How does cognitive therapy prevent depressive relapse and why should attentional control (mindfulness) training help? Behaviour Research and Therapy, 33(1), 25–39.

Young, Z. (2009), Enlightenment, DP/DR & Falling Into the Pit of the Void [video] Retrieved 2 February 2015 from: http://youtu.be/9zIKQCwDXsA

Prologue references

Britton, W. B., Lindahl, J. R., Cooper, D. J., Canby, N. K., & Palitsky, R. (2021). Defining and measuring meditation-related adverse effects in mindfulness-based programs. Clinical Psychological Science, 9(6), 1185–1204. https://doi.org/10.1177/2167702621996340

Geary, A. (2016). Mindfulness in clinical psychology and personal practice: do we know enough about the potential side effects of this cognitive intervention? Psych-Talk, September 2016. British Psychological Society.

Goldberg, S. B., Lam, S. U., Britton, W. B., & Davidson, R. J. (2022). Prevalence of meditation-related adverse effects in a population-based sample in the United States. Psychotherapy Research, 32(3), 291–305. https://doi.org/10.1080/10503307.2021.1933646

Lindahl, J. R., Fisher, N. E., Cooper, D. J., Rosen, R. K., & Britton, W. B. (2017). The varieties of contemplative experience: A mixed-methods study of meditation-related challenges in Western Buddhists. PLOS ONE, 12(5), e0176239. https://doi.org/10.1371/journal.pone.0176239

Lindahl, J. R., Britton, W. B., Cooper, D. J., & Kirmayer, L. J. (2020). Progress or pathology? Differential diagnosis and intervention criteria for meditation-related challenges: Perspectives from Buddhist meditation teachers and practitioners. Frontiers in Psychology, 11, 1905. https://doi.org/10.3389/fpsyg.2020.01905