Background
Bipolar Disorder (BD) is a common and severe form of mental illness. Pharmacotherapy is the main treatment offered, but has limited effectiveness, and there is increasing evidence that people with BD respond well to psychological interventions. Inequalities in access to face-to-face psychological interventions mean many people seek support outside of routine health services.

Aim
To assess a recovery informed web-based self-management intervention for BD to increase access to psychological support.

Method
A small online randomised controlled trial (RCT) will evaluate the feasibility, acceptability and potential effectiveness of the intervention compared to treatment as usual (TAU). Feasibility and acceptability will be assessed by recruitment, adherence and dropout rates, website usage statistics, user satisfaction scales and a series of qualitative interviews. Effectiveness will be assessed on a range of outcome measures including quality of life, mood symptoms, coping, recovery, and illness beliefs.

Analysis
Rates of adherence and dropout will be analysed using logistic regression models with health, socioeconomic and treatment factors as explanatory variables. Changes in quality of life mean scores, contrasting between arms, will be assessed using random effects models. An exploratory analysis will be performed on the secondary outcomes. Thematic analysis (Braun & Clarke, 2006) will be used to analyse the qualitative interviews.

Discussion
The benefits, challenges and methodological challenges of developing a web-based intervention and conducting an RCT online are discussed.

Conclusion
The results of this trial will inform a definitive trial; and the implementation phase will aim to assess the potential for use within the NHS.