By Mary Carpenter
THE BENEFITS of meditation—well supported by research—range from anxiety reduction to total life improvement. But recent investigations have revealed unpleasant or unwanted effects in around 25% of participants; the incidence is lower among women and those with strong religious beliefs.
Psychotic symptoms—hallucinations, delusions and disordered thought and speech—are among meditation’s worst risks. A 2019 Harper’s article tells the story of Megan Vogt, whose psychotic symptoms and suicidal thoughts increased over 10 days of an intense meditation retreat.
More than 50 published studies have documented meditation-induced psychosis, mania and dissociation, according to Harper’s. And “not-uncommon” adverse effects—including anxiety, depression and cognitive impairment—arose during 65% of studies reviewed by a Scandinavian journal in 2019.
Among 342 experienced meditators surveyed in the first large study, 25.4% reported “unwanted or “adverse” reactions—more likely when practicing alone and associated with the length of meditation. And a later survey of 1,232 regular meditators found 315 (25.6%) reporting similar “unpleasant experiences.”
“Every meditation center had at least a dozen horror stories,” said Brown University neuroscientist and psychologist Willoughby Britton, one of the first to investigate meditation’s risks. The most-debilitating meditation experiences occurred during multiday retreats, like the one Vogt did, that include fasting and sleep deprivation—with activities beginning before dawn and lasting 10 or more cumulative hours—along with restrictions on exercise and interactions with other meditators.
“The brain is accustomed to a certain amount of activity,” Harvard neuroscientist Matcheri Keshavan told Harper’s. When someone sits motionless with their eyes closed for 10 or more hours a day, neurons can start firing on their own—that “might lead to unusual phenomena, which we call psychosis,” said Keshavan.
Negative psychological effects are more likely to emerge with the “focused-attention” (FA) meditation commonly practiced at long retreats. As in the Vipassana meditation at Vogt’s retreat, FA practitioners concentrate on tasks like mental scans of the body and different methods of breathing with the goal of clearing their minds of everything else—and specifically of restricting mind wandering.
“Open monitoring” (OM) meditation, on the other hand, encourages mind wandering and paying attention to that as well as to sensations in the body. “Mindfulness meditation” includes both focused-attention and open-monitoring.
Both kinds of meditation reduce activation of the brain’s “default mode network” (DMN), the so-called “emotional brain” where feelings, behavior and motivation—everything from depression to creativity —arise. The DMN may also produce rigid habitual thinking, obsessions and addictions.
As a result, DMN functions may generate “awareness of the self”—in the moment and in different environments. The brain regions involved in the DMN operate on “a plethora of introspection-related functions, including self-reflection, mind wandering, autobiographical memory recollection, mental time travel to the future and imagination more broadly,” according to Robin Carhart-Harris and colleagues at London’s Psychedelics Research Group.
Not just a goal of meditation, bypassing the DMN can also facilitate psychedelic therapy—an experience called “drug-induced ego dissolution”—putting the ego out of commission by dissolving boundaries between self and the world, according to Johns Hopkins psychologist Matthew Johnson, who researches the effects of psilocybin (magic mushrooms).
Meditation research, however, is fraught with challenges: reliance on studies of individual cases rather than evidence from large groups and dependence on surveys taken following meditation experiences. Among hundreds of meditation surveys published each year, very few include questions about negative effects. In the only prospective study (as of 2019) of meditation-related difficulties, two (7%) of 27 participants, enrolled before participating in a Vipassana retreat, reported “profound adverse effects” leading them to discontinue the meditation.
A significant problem is the unreliability of self-reports by meditators. A 2014 Carnegie Mellon University study found that meditators who reported decreased stress actually had increased levels of the stress hormone cortisol. And among 12 subjects who reported sleeping better since beginning five-day per week meditations, six who meditated longer than 30 minutes had shallower sleep and woke more often than a control group. Sleep quality improved only for those who meditated for 30 minutes or less.
Disagreement about negative meditation experiences centers on whether these occur exclusively in individuals with pre-existing, underlying psychiatric conditions or vulnerability. Says Jeffrey Lieberman, past president of the American Psychiatric Association: “I don’t think meditation by itself can cause this.”
But in Britton’s study of 60 experienced meditators, 43 had “moderate to severe impairment” of their day-to-day functioning, with 10—most of whom had no pre-existing psychiatric condition—requiring inpatient hospitalization. ”It’s easy to assign a latent vulnerability after the fact,” Britton told Harper’s, “but we are seeing people who really had no indicators.”
The Scandinavian review also concluded that adverse effects “may occur in individuals with no previous history of mental health problems.” And a Dutch systematic review of 19 reports of “potentially meditation-induced psychosis” found that in half of the 28 cases, 14 had no prior diagnosis.
In most studies, length of meditation is a key variable in cases of adverse effects—with participants meditating for 30 minutes or less reporting positive experiences compared to those who meditated for longer periods. Other variables related to difficult meditation experiences include relationships (isolation of participants), health behaviors (restrictions on sleep, diet and exercise) and practitioner vulnerability.
What may be most important for safe meditation experiences is the quality of instructors—notably the relationships they establish with participants, both before and during the meditations, which should include learning about each individual’s strengths and vulnerabilities.
Britton and other meditation researchers have created a “safety tool-box” for meditation leaders. For meditators in trouble, the online support group Cheetah House based at Brown University and facilitated by Britton offers resources and support, including first-hand accounts of “meditation-induced medical emergencies.” One poster wrote on the site, “Cheetah House literally saved my life.”
During her retreat, Megan Vogt appeared to lose her sense of self and to dissociate from reality —goals of the meditation but devastating to her. More than 60 hours after she began having symptoms and had gone days without sleeping, the staff failed to contact Megan’s therapist (who had agreed to be available) but finally called her family to come take her home. Despite having in-patient psychiatric treatment and cautious, watchful family members, within months of the retreat Vogt committed suicide.
For an eight-week Mindfulness Based Stress Reduction (MBSR) class at the Insight Medication Community of Washington,” I received a long, chatty introductory phone call from the class instructor Bill Mies—which in hindsight probably included an assessment of me. By our first class, Mies appeared on familiar terms with most of the students. Perhaps that’s why, also in hindsight, that first night I felt unworried by the serious-sounding mental health issues described by some of the students—and comforted by the easy familiarity that Mies created for the class.
—Mary Carpenter regularly reports on topical issues in health and medicine.