Transcranial Magnetic Stimulation for Bipolar Depression

A Comparison of Left vs. Right Prefrontal Cortex Transcranial Magnetic Stimulation as a Treatment for Bipolar Depression

This is a study to assess the effectiveness of repetitive transcranial magnetic stimulation (rTMS) as a treatment for depressed adults with bipolar disorder.

In rTMS high-intensity, fluctuating magnetic fields non-invasively stimulate the cortex of the brain depolarising neurons. No anaesthetic is required and the treatment in subconvulsive. Recent studies suggest that rTMS can be an effective treatment for depressive illness in adults (Loo and Mitchell et al, 2005) and appears to be quite safe.

Most of the published studies to date have focused on unipolar depression. There is limited data of TMS use in bipolar depression. Eg. Pilot study by Nahas Z, Kozel FA, Li X, Anderson B, George MS.in 2003, which was negative.

The investigators wish to assess this in a sham-controlled study of adults. The investigators hypothesise that both left and right sided rTMS will have an antidepressant effect superior to sham in this population.

Inpatients and outpatients with major depressive episodes as part of either bipolar I or II illness will be eligible. In the event that patients (in any arm) have no significant response after a defined period, they will shift to an open phase where they will receive left prefrontal 10Hz stimulation. Thus all participants will have the opportunity to receive active treatment.

Inclusion Criteria:

• DSM-IV Major Depressive Episode of no more than 3 years.
• Diagnosis of bipolar I or II disorder
• Montgomery-Asberg Depression Rating Scale score of 20 or more.
• Aged over 18
• May or may not be taking antidepressant medication.

Exclusion Criteria:

• Patient not able to give informed consent.
• Failure to respond to ECT in current episode of depression.
• Significant other Axis I psychiatric disorders e.g. schizophrenia.
• In imminent physical or psychological danger, or needs rapid clinical response due to inanition, psychosis or high suicide risk.
• Comorbid substance abuse or dependence
• History of neurological illness e.g. epilepsy; neurosurgical procedure
• Metal in the cranium, a pacemaker, cochlear implant, medication pump or other electronic device.
• Women of child-bearing age in whom pregnancy cannot be ruled out.
• Patients with a history of mood 'switching' in response to other treatments.