Vipassana meditation: systematic review of current evidence.

OBJECTIVES: Vipassana meditation (VM) is one of the most ancient and diffused types of meditative practices belonging to the pole of mindfulness. Despite the growing interest toward the neurobiological and clinical correlates of many meditative practices, no review has specifically focused on current evidence on neuro-imaging and clinical evidence about VM.
METHODS: A literature search was undertaken using MEDLINE,((R)) ISI web of knowledge, the Cochrane database, and references of retrieved articles. Controlled and cross-sectional studies with controls published in English up to March 2009 were included.
RESULTS: Seven (7) mainly poor-quality studies were identified. Three (3) neuro-imaging studies suggested that VM practice could be associated with the activation of the prefrontal and the anterior cingulate cortex during meditative periods, and with increased thickness in cortical areas related to attention as well as increased subcortical gray matter in right insula and hippocampus in long-term meditators. Three (3) clinical studies in incarcerated populations suggested that VM could reduce alcohol and substance abuse but not post-traumatic stress disorder symptoms in prisoners. One (1) clinical study in healthy subjects suggested that VM could enhance more mature defenses and copying styles. DISCUSSION: Current studies provided preliminary results about neurobiological and clinical changes related to VM practice. Nonetheless, few and mainly low-quality data are available especially for clinical studies and current results have to be considered with caution. Further research is needed to answer critical questions about replications, self-selection, placebo, and long-term effects of VM.