To understand why people are experiencing short- or long-term adverse reactions to meditation and mindfulness, Britton says more research is needed. However, there are some theories. Britton says that the 6% who reported long-term negative side effects tended to meditate more. Duration as a risk factor for "unpleasant" meditation experiences has been previously reported in people who go on retreats, where meditation is done 12 to 15 hours a day.5 In addition to duration, context and culture should be considered.
