This is a protocol for a Cochrane Review (intervention). The objectives are as follows: 1. To study the effects of BA in comparison with other psychological therapies (e.g. mindfulness therapy, CBT, dialectical behavioural therapy) for anxiety disorders in adults. 2. To study the effects of BA compared with pharmacotherapy for anxiety disorders in adults. 3. To study the effects of BA compared with treatment as usual, waiting list, placebo, and no treatment for anxiety disorders in adults
