Acceptance and commitment therapy and depression: the development of a depression specific process measure

The aim of this study was to develop a self report measure to assess the core processes of Acceptance and Commitment Therapy (ACT) as they apply to depressed individuals in the interest of further assessing the role of these processes in mediating depression. One hundred and twenty clinically depressed participants and a control sample of 121 first and second year psychology university students participated. Participants in both groups completed a battery of questionnaires including demographic and mental health history, Acceptance and Avoidance Questionnaire for Depression (AAQ-D), Acceptance and Avoidance Questionnaire II (AAQ-II), Mindfulness Attention and Awareness Scale, White Bear Suppression Inventory, Outcome Questionnaire, Beck Depression Inventory Second Edition (BDI-II), Reasons for Depression Scale, and a modified version of the Automatic Thought Questionnaire. One hundred and forty eight participants completed a two week follow up including the AAQ-D, AAQII and the BDI-II. The results of this study suggest the AAQ-D is a reliable and valid measure of ACT processes relevant to depression. The factor analysis of the AAQ-D produced a three factor structure with a general factor assessing psychological flexibility, and two second order factors measuring Mindfulness and Defusion and Values and Committed Action.