Deep Brain Stimulation for Depression and OCD
Benefits and Drawbacks of DBS in Severe Psychiatric Disorders
In the context of psychiatric disorders, the term “treatment-refractory” is used in cases where conventional interventions have repeatedly failed. A person with treatment-refractory depression, for example, may have had no success from trying several antidepressant drugs, psychological therapies and sometimes electroconvulsive therapy.
Deep Brain Stimulation (DBS)
DBS is a type of neurostimulation therapy where electric current is used to stimulate areas in the brain directly. It is better known for its use in the symptom management of Parkinson’s disease, for which it is currently an FDA-approved treatment. It is not an approved treatment for depression and OCD but is currently being investigated.
A patient receiving DBS is given local anaesthesia and so remains awake. Two small holes are drilled into the skull and electrodes are then inserted bilaterally into targeted areas of the brain. These areas are then stimulated by electric current. A small battery is implanted in the chest or abdomen, allowing a continual supply of this current.
Research into DBS for Depression and OCD
Dr Helen Mayberg, professor of psychiatry and neurology at Emory University, headed a pilot study into DBS and treatment-refractory depression in 2002. The specific part of the brain targeted is an area of white matter next to the subgenual area (also known as Brodmann area 25). This part of the brain links into a number of pathways relating to stress, sleep, mood and emotional regulation.
Four out of the six patients in Mayberg’s study responded well to the treatment, measured by a 50% reduction in symptoms using the Hamilton Rating Scale for Depression. Some of the patients described feeling better shortly after the current was activated. The four patients have remained well since the study.
A small number of similar studies have followed Mayberg’s, with similar results. Several other studies are in progress or are due to be conducted, including a controlled, blinded study. Some of these studies have looked specifically at treatment-refractory OCD. A small number of participants experienced complications such as seizures.
Advantages of DBS for Depression and OCD
- It may dramatically reduce symptoms, thereby decreasing the risk of suicide and increasing the quality of life.
- It is less invasive and non-permanent, compared with other surgical options for treatment-refractory OCD.
- The current and voltage can be adjusted to suit the individual.
- DBS is completely reversible, and so can be stopped if necessary.
Disadvantages of DBS for Depression and OCD
- DBS carries the same serious risks as other brain surgeries, including risk of haemorrhage, seizures and infections.
- It is currently experimental, and therefore there is little known about long-term effects and why some people don’t respond to it.
- DBS can be physically uncomfortable.
- Insurers may not cover the treatment.
The Future of DBS for Depression and OCD
It is still early days, but DBS appears to be a promising treatment for depression and OCD. It is also being considered as a possible treatment for bipolar disorder. Many neurosurgeons already practice DBS for Parkinson’s patients, so are already equipped to perform it.
For more information on DBS, including case studies, read Deep Brain Stimulation: A New Treatment Shows Promise in the Most Difficult Cases, by Jamie Talan and Richard Firstman. This book is due to be released in August 2008. Those experiencing symptoms of depression and/or OCD should seek advice from a qualified health practitioner.
Sources
Deep brain stimulation for treatment-resistant depression, Neuron, published: March 2005, authors: Mayberg, H. et al.
Deep Brain Stimulation Studied for Depression, Psychiatric News, published: June 2008, author: Yan, J.
