The role of psychological flexibility in a self-help acceptance and commitment therapy intervention for psychological distress in a randomized controlled trial

The Parent Psychological Flexibility Questionnaire (PPFQ): Item Reduction and Validation in a Clinical Sample of Swedish Parents of Children with Chronic Pain

In pediatric chronic pain, research indicates a positive relation between parental psychological flexibility (i.e., the parent’s willingness to experience distress related to the child’s pain in the service of valued behavior) and level of functioning in the child. This points to the utility of targeting parental psychological flexibility in pediatric chronic pain. The Parent Psychological Flexibility Questionnaire (PPFQ) is currently the only instrument developed for this purpose, and two previous studies have indicated its reliability and validity. The current study sought to validate the Swedish version of the 17-item PPFQ (PPFQ-17) in a sample of parents (n = 263) of children with chronic pain. Factor structure and internal reliability were evaluated by means of principal component analysis (PCA) and Cronbach’s alpha. Concurrent criterion validity was examined by hierarchical multiple regression analyses with parental anxiety and depression as outcomes. The PCA supported a three-factor solution with 10 items explaining 69.5% of the total variance. Cronbach’s alpha (0.86) indicated good internal consistency. The 10-item PPFQ (PPFQ-10) further explained a significant amount of variance in anxiety (29%), and depression (35.6%), confirming concurrent validity. In conclusion, results support the reliability and validity of the PPFQ-10, and suggest its usefulness in assessing psychological flexibility in parents of children with chronic pain.

Mechanisms of change in psychotherapy for depression: An empirical update and evaluation of research aimed at identifying psychological mediators

We present a systematic empirical update and critical evaluation of the current status of research aimed at identifying a variety of psychological mediators in various forms of psychotherapy for depression. We summarize study characteristics and results of 35 relevant studies, and discuss the extent to which these studies meet several important requirements for mechanism research. Our review indicates that in spite of increased attention for the topic, advances in theoretical consensus about necessities for mechanism research, and sophistication of study designs, research in this field is still heterogeneous and unsatisfactory in methodological respect. Probably the biggest challenge in the field is demonstrating the causal relation between change in the mediator and change in depressive symptoms. The field would benefit from a further refinement of research methods to identify processes of therapeutic change. Recommendations for future research are discussed. However, even in the most optimal research designs, explaining psychotherapeutic change remains a challenge. Psychotherapy is a multi-dimensional phenomenon that might work through interplay of multiple mechanisms at several levels. As a result, it might be too complex to be explained in relatively simple causal models of psychological change.

How and for whom does web-based acceptance and commitment therapy work? Mediation and moderation analyses of web-based ACT for depressive symptoms

BACKGROUND

Acceptance and Commitment Therapy (ACT) has been demonstrated to be effective in reducing depressive symptoms. However, little is known how and for whom therapeutic change occurs, specifically in web-based interventions. This study focuses on the mediators, moderators and predictors of change during a web-based ACT intervention.

METHODS

Data from 236 adults from the general population with mild to moderate depressive symptoms, randomized to either web-based ACT (n = 82) or one of two control conditions (web-based Expressive Writing (EW; n = 67) and a waiting list (n = 87)), were analysed. Single and multiple mediation analyses, and exploratory linear regression analyses were performed using PROCESS and linear regression analyses, to examine mediators, moderators and predictors on pre- to post- and follow-up treatment change of depressive symptoms.

RESULTS

The treatment effect of ACT versus the waiting list was mediated by psychological flexibility and two mindfulness facets. The treatment effect of ACT versus EW was not significantly mediated. The moderator analyses demonstrated that the effects of web-based ACT did not vary according to baseline patient characteristics when compared to both control groups. However, higher baseline depressive symptoms and positive mental health and lower baseline anxiety were identified as predictors of outcome across all conditions. Similar results are found for follow-up.

CONCLUSIONS

The findings of this study corroborate the evidence that psychological flexibility and mindfulness are distinct process mechanisms that mediate the effects of web-based ACT intervention. The results indicate that there are no restrictions to the allocation of web-based ACT intervention and that web-based ACT can work for different subpopulations.

TRIAL REGISTRATION

Netherlands Trial Register NTR2736 . Registered 6 February 2011.