To examine the clinical and cost-effectiveness of a lifestyle-based approach to treating anxiety and Panic Disorder in Primary Care. To present evidence from an explanatory model.

A Pragmatic Randomised Controlled Trial was conducted comparing a lifestyle intervention with routine GP care. The lifestyle intervention used patient diary data focusing on diet, fluid intake, habitual lifestyle drug use (alcohol, nicotine and caffeine) and exercise, to influence mood and behaviour change. Following the MRC (2008) recommendation on developing and evaluating complex interventions, an explanatory model was developed.

31 Lifestyle arm and 36 GP care arm patients completed to analysis. A significant improvement in Beck Anxiety Inventory scores was observed at end of treatment (Lifestyle 29.5 to 9.2; GP 29.4 to 17.2; p< 0.001) although non-significant at 10 month follow-up (Lifestyle 13.3: GP 16.4; p=0.167). Results were comparable with full CBT and improved compared with medication. Cost-effectiveness analysis showed that If maximum willingness to pay peradditional QALY is £30,000, this represents an 86% chance that a lifestyle intervention provides value for money over 10 months. Modeling shows a broad range of factors influencing anxiety and panic responses, indicating that lifestyle interventions impact at a different point in the system to medication and psychological approaches.

Evidence shows that a lifestyle-based intervention provides an additional, cost-effective intervention and significantly improved symptom profile for anxiety and panic disorder compared with routine GP care. It impacts on both physiological and cognitive symptoms. Modeling suggests broader application to other mental health problems.