Peak Experiences During Insight Mindfulness Meditation Retreats and Their Salutary and Adverse Impact: A Prospective Matched-Controlled Intervention Study

Objective: We sought to address a growing debate regarding the adverse and salutary impact of unusual, extraordinary or intense subjective experiences during meditation-based interventions. To do so, we empirically characterized such peak experiences during an intensive meditation intervention and their impact postintervention. Method: We conducted a preregistered prospective intervention study among 96 adults who registered for 6-day insight (Vipassana) mindfulness meditation retreats and 47 matched controls. Controls were selected from a pool of 543 people recruited from the same community of meditators as retreat participants and systematically matched to retreat participants on age and lifetime meditation experience. Measures included the novel Peak Meditative Experience Scale and the Impact of PMES. Results: Seventeen peak experiences that were primarily pleasant (e.g., deep and unusual peace, aha! Moment) occurred more frequently among retreat participants than among matched controls in daily living (ps <.05; mean ϕ =.33). In contrast, 14 peak experiences that were mostly unpleasant (e.g., flashbacks, overwhelming sadness) occurred at similar rates in both groups (ps?>.05). At 2-week follow-up, the perceived impact of all pleasant and most unpleasant peak experiences was more salutary than adverse (ps ≤.015;M Cohen’s d = 1.61). Conclusions: Peak experiences that resulted from meditation retreats were primarily pleasant and had a large salutary impact postretreat. Inconsistent with conclusions from uncontrolled retrospective studies, findings document that intensive insight mindfulness meditation training in retreats may not contribute to unpleasant peak experiences and even when they occurred their impact was typically more salutary than adverse.