Posttraumatic stress disorder (PTSD) is a debilitating condition that emerges after exposure to a traumatic event. Meditation may provide a safe, self-administered, and inexpensive complement to first-line treatments for PTSD. This systematic review synthesized evidence on meditation interventions for the treatment of PTSD (PROSPERO 2015: CRD42015025782).
We searched eight electronic databases from inception to November 2015 and bibliographies of existing systematic reviews to identify English-language randomized controlled trials (RCTs) evaluating the efficacy and safety of meditation interventions in patients with PTSD. Two independent reviewers screened identified literature using predetermined eligibility criteria, abstracted study-level information, and assessed study quality. Meta-analyses used the Hartung-Knapp-Sidik-Jonkman method for random-effects models. The quality of evidence was assessed using the GRADE approach. The primary outcome was PTSD symptom severity, and other outcomes included depression, anxiety, quality of life, functional status, and adverse events. Ten RCTs on meditation interventions for PTSD met inclusion criteria, including five studies of mindfulness-based stress reduction, three of yoga, and two of the mantram repetition program. Meditation approach, intervention intensity, and study quality varied considerably. Eight RCTs included patients exposed to combat-associated trauma, six of which focused exclusively on combat-related trauma. Meditation interventions offered as adjunctive therapy reduced PTSD symptoms postintervention compared with all comparators (treatment as usual alone, attention-matched control groups, present-centered group therapy) across all types of trauma (SMD −0.41; CI −0.81, −0.01; 8 RCTs; I 2 67%; n=517; low quality of evidence). Meditation was also effective
in reducing depression symptoms (SMD −0.34; CI −0.59, −0.08; 8 RCTs; I 2 24%; n=523; moderate quality of evidence). Effects were not statistically significant for quality of life (SMD 0.52; CI −0.24, 1.28; 4 RCTs; I 2 64%; n=337; very low quality of evidence) and anxiety (SMD −0.14; CI −0.63, 0.36; 3 RCTs; I 2 0%; n=234; moderate quality of evidence). No studies addressed functional status. There were no adverse events reported in intervention groups; however, only five RCTs assessed safety. No head-to-head trials compared different meditation approaches; indirect comparisons did not systematically favor one type of meditation over
another, but only a small number of studies were available per approach. It was not possible to determine the differential effect of meditation as monotherapy versus adjunctive therapy, and meta-regressions did not identify a systematic effect of the intervention intensity, trauma type, or type of comparator.
Across interventions, meditation improved PTSD symptoms and depression symptoms. However, these positive findings are based on low to moderate ratings of quality of evidence, and only a small number of studies were available in each meditation category. Additional high-quality trials with adequate power, and longer follow-ups are suggested.