Russell-Mayhew, ShellySaraceni, Reana2013-06-262013-11-122013-06-262013http://hdl.handle.net/11023/769Eating disorders are generally defined by abnormal eating habits that typically involve either the insufficient or excessive intake of food to the detriment of an individual’s physical and mental health. Eating disorders are amongst the most challenging disorders to treat, and even the treatment of choice, cognitive-behavioural therapy, only achieves moderate success. This study is in response to a call from experts in the field who recommend the piloting of promising therapies for these challenging disorders. Some of the reasons for treatment difficulties may be due to existing therapies failing to adequately respond to inflexible control strategies such as experiential avoidance, often seen in eating disorders. Acceptance and Commitment Therapy (ACT) directly targets psychological inflexibility, making it a potentially ideal treatment for disordered eating. ACT is an innovative treatment that has been applied broadly to a variety of disorders. This is the first study to examine the efficacy of a complete ACT intervention for women with clinical disordered eating. This study examines change over time on measures life quality, valued living, mindful acceptance and observing, disordered eating and psychological maladjustment. The utilization of individual growth curve analyses provides a statistical modeling technique that summarizes changes about intra-individual change while simultaneously addressing inter-individual differences in change. Duration of illness was utilized as a predictor to further explain the hypothesized change over time. The results of this seven week group intervention showed positive pre-test to follow-up improvements in life quality, valued living, experiential avoidance, disordered eating, and psychological maladjustment. The mindfulness results run counter to findings from mindfulness component studies for eating disorders. The results suggest that the cognitive (mindfulness) processes did not appear to add value above and beyond the commitment and behaviour change processes. No significant differences were found on any of the measures between women who reported shorter versus much longer durations of their illness. Overall, results suggest that the commitment to living a valued-based life may be the most viable component of and ACT intervention for treating women with disordered eating. Future research is warranted to parse out the behavioural aspect of ACT’s mindfulness-based behavioural approach to treatment.engUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.Educational PsychologyEducation--Guidance and CounselingMental HealthEating DisordersAcceptance and Commitment TherapyMindfulnessdoctoral thesis10.11575/PRISM/24953