Acceptance and Commitment Therapy (ACT) for rumination and worry in individuals with anxiety and depression: A randomized control trial

INTERVENTION: ACT is a mindfulness, acceptance and values‐based psychotherapy which proposes different processes of change and outcome compared to traditional cognitive and behavioural treatments (Hayes, Masuda, & De Mey, 2003). In ACT, acceptance, mindfulness and values strategies are used to create a context for an individual to engage in effective and valued behaviours, even in the presence of difficult thoughts and emotions. The intervention for this study is ACT delivered in group format, based on therapy protocols by Glaser, Blackledge, and Deane (2008) and Zettle (2007). It will consist of 8 X 2‐hour group sessions, delivered weekly. The therapy will be delivered by provisional psychologists. CONDITION: Anxiety disorders excluding Obsessive Compulsive Disorder and Post‐Traumatic Stress Disorder Dysthymic disorder Major depressive disorder PRIMARY OUTCOME: Depression, Anxiety and Stress Scales (DASS‐21) Penn State Worry Questionnaire (PSWQ) Ruminative Thought Style Questionnaire (RTS) SECONDARY OUTCOME: Acceptance and Action Questionnaire‐II (AAQ‐II) Automatic Thoughts Questionnaire (ATQ) Behavioural Activation for Depression Scale (BADS) Mindful Attention and Awareness Scale (MAAS) Sheehan Disability Scale Valued Living Questionnaire (VLQ) White Bear Suppression Inventory (WBSI) INCLUSION CRITERIA: A diagnosis of major depressive disorder, dysthymic disorder or an anxiety disorder where worry and rumination are prominent features. Each participant’s eligibility will be assessed using the depression and anxiety modules of the Structured Clinical Interview for DSM‐IV‐TR Axis I Disorders (Patient Edition, with Psychotic Screen; First, Gibbon, Spitzer, & Williams, 2007).