Psychological inflexibility and flexibility are associated with insomnia and sleep quality: A systematic review

Abstract

Acceptance and Commitment Therapy deals with psychological inflexibility by promoting psychological flexibility, and is effective for different disorders including insomnia. However, little is known about the nature of the relationship between psychological inflexibility and flexibility with insomnia and sleep quality. In order to assess which processes of inflexibility and flexibility may be most prominent in the relationship with sleep, a systematic review of the literature was carried out to characterize the nature of this relationship. The review included 19 articles, all of which found some kind of comparative, correlative, predictive or mediating relationship. Thus, psychological inflexibility and psychological flexibility seem to be associated with insomnia and sleep quality, with emphasis on the processes of acceptance/ experiential avoidance, defusion/fusion and value-based actions/inaction. Therefore, psychological flexibility may be a protective factor, while psychological inflexibility a predisposing and perpetuating factor for insomnia severity and sleep quality.