Preliminary results from a pilot study demonstrated that cognitive behavioural therapy (CBT) is associated with a significant benefit for patients with dissociative seizures. The current study aims to extend these findings by conducting a randomised controlled trial comparing CBT with standard outpatient medical care. Standard outpatient care has been chosen as the comparison treatment as it most closely resembles what is currently offered to this group of patients by the National Health Service. The primary outcome measure will be seizure frequency. Secondary outcome measures will be work and social adjustment and health service use.