Associations Between Six Core Processes of Psychological Flexibility with Poor Sleep Outcomes: A Systematic Review and Meta-Analysis

While acceptance and commitment therapy (ACT) is one of the effective treatments for insomnia, one of the challenges in treating sleep disorders is unawareness of the role of the core processes of ACT. The present systematic review aimed to investigate the associations between the six core processes of psychological flexibility (i.e., acceptance, cognitive defusion, being at present or mindfulness, committed action, self as context, and values) and poor sleep outcomes including poor sleep quality (PSQ) and insomnia severity. PubMed and Scopus were searched to identify the academic articles published between 2000 and 2022 (PROSPERO- CRD42022381181).

Pooled estimates of correlations were calculated using the random-effects method. The pooled effect sizes obtained from 28 studies showed significant correlations between four components of ACT and poor sleep outcomes. Meta-regression results showed that the negative correlation between acceptance and PSQ is significantly affected by the mean age of the samples across the studies (p = 0.042). Although the association between ACT components and PSQ was relatively stronger in studies with small sample sizes and those conducted only on women, none of these differences were statistically significant (p > 0.05).

It can be argued that four components of core processes of psychological flexibility are negatively correlated with poor sleep outcomes. Clinicians and therapists need to take into account these components when trying to treat insomnia and improve sleep quality.