Effectiveness of acceptance and commitment therapy (ACT) in enhancing psychological flexibility in adults: a systematic review; and, Wellbeing in retirement: the role of psychological flexibility, value-directed living and cognitive defusion
This thesis aimed to explore the applicability and effectiveness of the Acceptance and Commitment Therapy (ACT) model. The first chapter is a systematic review of the effectiveness of ACT in enhancing psychological flexibility in adults. The review found good evidence from the eleven included studies that ACT treatments are effective. There was preliminary evidence that ACT was more effective than other treatments, but results were not conclusive. Further research using theoretically-consistent measures is recommended. The second chapter is an empirical study exploring the role of ACT processes in retirement. A cross-sectional survey completed by 181 retired people explored value-directed living, cognitive defusion and psychological flexibility in predicting wellbeing, adjustment and distress. Correlation analyses and multiple hierarchical regression analyses were conducted. The psychological factors were found to explain unique variance in these outcome variables, even when the variance from known predictors such as physical health had been accounted for. Psychological flexibility was found to be the strongest predictor of wellbeing, adjustment and distress. These findings need to be replicated in longitudinal research, however they provide initial evidence that interventions aimed at improving psychological flexibility could be beneficial for people in retirement.