Evidence
Mindfulness: risks, side effects and the limits of the evidence
Mindfulness is usually described as low risk, yet reviews report side effects and the research has gaps. Here is what the sources found, and what they leave open.
Mindfulness is promoted widely, and most coverage focuses on benefits. A fair account also has to cover the people for whom it goes badly, the questions that research has not answered, and the quality of the studies behind the headlines. This page draws on a federal research agency, two health information services and two peer-reviewed papers, and it reports only what those sources say.
For a plain introduction first, read what happens when you do mindfulness meditation.
What the main US agency says about safety
The US National Center for Complementary and Integrative Health (NCCIH) says that meditation and mindfulness practices usually are considered to have few risks. It adds immediately that few studies have examined these practices for potentially harmful effects, so it is not possible to make definite statements about safety.
The page points to a 2020 review of 83 studies with 6,703 participants. Of those studies, 55 reported negative experiences linked to meditation. The researchers concluded that about 8 percent of participants had a negative effect, which NCCIH says is similar to the percentage reported for psychological therapies. The most commonly reported negative effects were anxiety and depression. In a smaller analysis of three studies of mindfulness-based stress reduction, with 521 participants, the practices were not more harmful than no treatment.
What the peer-reviewed reviews found
The review NCCIH refers to is Farias and colleagues, published in 2020 in Acta Psychiatrica Scandinavica. The overall prevalence of adverse events was 8.3 percent, but the figure differed sharply by study design: 3.7 percent in experimental studies and 33.2 percent in observational studies. The most common events were anxiety (33 percent of the studies reporting events), depression (27 percent) and cognitive anomalies (25 percent). The authors concluded that adverse events may occur in people with no previous history of mental health problems.
A second paper, Britton and colleagues in Clinical Psychological Science in 2021, used a structured interview with a set list of possible side effects. An independent assessor asked 96 people who had taken one of three versions of an eight-week mindfulness-based cognitive therapy programme about 44 possible side effects. Eighty-three percent reported at least one meditation-related side effect. Effects with a negative feel or a negative impact on functioning occurred in 58 percent and 37 percent of the sample. Lasting bad effects occurred in 6 to 14 percent, and these were associated with signs of dysregulated arousal, specifically hyperarousal and dissociation. The authors conclude that the rates are similar to those of other psychological treatments.
The gap between 8 percent and 83 percent shows how much the answer depends on how the question is asked. Neither abstract says mindfulness is dangerous in general. A "side effect" in the Britton study also includes brief, temporary distress, not only lasting harm.
Who may need extra care
The sources the editors opened do not give a firm list of people who should avoid mindfulness. Farias and colleagues found events in people with no history of mental health problems, so a clean history is not a guarantee. Britton and colleagues link lasting problems to hyperarousal and dissociation, which suggests that anyone who notices feeling detached, panicky or keyed up during practice has reason to pause.
Mind, the UK mental health charity, offers practical questions. It says that acknowledging difficult thoughts can sometimes be distressing and could make you feel worse at first, and that if the exercises are hard to do, it is best to get advice from a trained professional. It also asks whether you are well enough to start something new right now, noting that if you are feeling very unwell you might need more treatment and support in place first. The NHS says mindfulness is not right for everyone, and that some people find it does not help or even makes them feel worse.
The limits of the evidence
NCCIH is blunt about research quality. It says much of the research on mindfulness and meditation has been preliminary or not scientifically rigorous, that the studies cover many different practices whose effects are hard to measure, and that results may have been interpreted too optimistically. It describes a 2021 analysis in which the risk of bias was unclear and the few studies with follow-up beyond two months found no long-term effects, and a 2019 review of university students in which most studies were of poor quality.
A 2018 paper in Perspectives on Psychological Science, "Mind the Hype", by a group of mindfulness researchers, makes a related point. Its authors say that misinformation and poor methodology in past studies may lead consumers to be harmed, misled and disappointed. They discuss the difficulty of defining mindfulness and set out a research agenda that includes attention to adverse effects. The NHS says studies show mindfulness can help with stress, anxiety and depression, but that more research is needed for other conditions. Mind notes that NICE, the UK health guidance body, does not recommend mindfulness-based treatments for social anxiety because there is not enough evidence. For a fuller look at the anxiety research, see does mindfulness work for anxiety and mindfulness programmes: MBSR and MBCT.
Not a replacement for care
NCCIH advises against using meditation or mindfulness to replace conventional care or as a reason to postpone seeing a health care provider about a medical problem. It also suggests asking about the training and experience of any instructor. If a practice such as the body scan walkthrough or the mindful minutes timer feels unpleasant, stopping is a reasonable response. When self-help is not enough covers how to reach professional support.
Common questions
Is mindfulness dangerous?
The sources do not describe it as dangerous in general. NCCIH says it usually is considered to have few risks, while also saying that too few studies have looked at harm to make definite safety claims.
Why do the harm figures vary so much?
The Farias review found 3.7 percent in experimental studies and 33.2 percent in observational studies. The Britton study found 83 percent reporting any side effect when each one was asked about directly. Definitions, methods and the severity counted all differ.
What should I do if practice makes me feel worse?
Mind advises getting advice from a trained professional if exercises are hard to do or distressing. NCCIH advises telling your health care providers about any complementary approach you use.
The short version
Mindfulness is usually considered low risk, but the research on harm is thin, and reviews report side effects such as anxiety, depression and dissociation in a minority of participants, with rates that depend heavily on how they were measured. The wider evidence base has quality problems, and the sources agree that it should not replace conventional care.