Anxiety, mood and trauma-related disorders are common, affecting up to 20% of adults. Many of these individuals will experience symptoms of more than one disorder as diagnostically defined. However, most psychological treatments focus on individual disorders and are less effective for those who experience comorbid disorders.

The new protocol paper from CBU scientists, Tim Dalgleish, Anna Bevan, Peter Watson, Caitlin Hitchcock, Rachel Elliott, David Johnston, Melissa Black, explains how The HARMONIC trial introduces a novel transdiagnostic intervention (Shaping Healthy Minds), which synthesises several evidence-based treatment techniques to address the gap in effective interventions for people with complex and comorbid difficulties. This early-phase trial aims to estimate the efficacy and feasibility of the transdiagnostic intervention in preparation for a later-phase randomised controlled trial, and to explore mechanisms of change.

Methods/Analysis: The scientists outline a patient-level two-arm randomised controlled trial (HARMONIC) that compares Shaping Healthy Minds to treatment-as-usual (TAU) for individuals aged >18 years (N=50) with co-morbid mood, anxiety, obsessive-compulsive or trauma/stressor disorder diagnoses, recruited from outpatient psychological services within the UK National Health Service. The co-primary outcomes will be 3-month follow-up scores on self-report measures of depressive symptoms, anxiety symptoms, and disability and functional impairment. Secondary outcomes include changes in symptoms linked to individual disorders. We will assess the feasibility and acceptability of Shaping Healthy Minds, the utility of proposed outcome measures, and refine the treatment manuals in preparation for a later-phase trial.

Ethics and dissemination: This trial protocol has been approved by the Health Research Authority of the National Health Service of the United Kingdom (East of England, Reference: 16/EE/0095). We anticipate that trial findings will inform future revisions of clinical guidelines for numerous forms of mood, anxiety, and stressor-related disorders. Findings will be disseminated broadly via peer-reviewed empirical journal articles, conference presentations, clinical workshops, and a trial website.

More information about the HARMONIC trial: c2ad.mrc-cbu.cam.ac.uk/harmonic