Meditation, mindfulness, and acceptance methods in psychotherapy: A systematic review.

Objective: : Meditation, mindfulness, and acceptance (MMA) methods have gained popularity among psychotherapists and the public. The impact of these strategies as implemented in treatment packages (e.g., mindfulness-based interventions) has been studied extensively. However, the impact of integrating MMA strategies into individual psychotherapy has not been established.
Methods: : To address this gap in the literature, we conducted a systematic review of empirical (quantitative or qualitative) studies investigating the use of MMA methods during individual psychotherapy in adult samples.
Results: : After reviewing 4671 references, only three studies (one quantitative, two qualitative) met our inclusion criteria. The one experimental study ( n  = 162) provided no evidence that including mindfulness meditation improved outcomes beyond other active interventions ( d s = 0.00-0.12 for effects on general clinical symptoms vs. progressive muscle relaxation and treatment-as-usual, respectively). Two qualitative studies ( n  = 5 therapist-patient dyads in one study, n  = 9 adults in one study) provided preliminary evidence that patients may find MMA methods helpful.
Conclusions: : We highlight future directions for work in this area, including clarifying optimal dosage and timing, identifying patient characteristics associated with beneficial or adverse effects, investigating cultural adaptations, and clarifying how MMA constructs can be measured within individual psychotherapy. We conclude by highlighting training recommendations and therapeutic practices.