The 39th T S Srinivasan Endowment Oration titled “Rethinking Depression and its Treatment – Stimulating the Brain to Heal the Mind” was delivered this year, by Prof. Helen S Mayberg MD, Director-Centre for Advanced Circuit Therapeutics, Icahn School of Medicine at Mount Sinai, New York at the ITC Grand Chola Hotel, Chennai.
Prof. Mayberg’s oration detailed the progress that was being made in treating depression by combining new technologies with enhanced imaging techniques to improve predictability. Depression is a condition where human emotions become altered significantly resulting in abnormalities of mood, emotional experience and expression, self-confidence and functional ability.
Accompanied by a host of biological function disturbances (sleep, appetite and sexual function all being affected), it is the most common mental health problem worldwide. It also causes significant disability globally and can affect anyone, at any age. 10% of all people in the world suffer from depression, with India, China and US being the top three. Prof. Mayberg said that antidepressants and psychotherapy can provide relief in people with persistent depressive disorders and can help them to resume a normal life. But for those who experience treatment-resistant depression (TRD), standard medications and therapies tend to provide little to no relief. This is where treatment technologies such as Deep Brain Stimulation (DBS) come into play.
DBS is an emerging treatment strategy for patients with intractable depression which uses high-frequency electrical stimulation that is targeted to a specific or localized area of the brain. Use of specialized scanning techniques to map depression in the brain plays a crucial role in the development, testing and refinement of the procedure. DBS can be likened to a pacemaker for the brain and is similar to DBS implants used in patients with Parkinson’s disease. It involves a procedure that surgically implants paired electrodes into a region called subcallosal cingulate cortex or SCC, near the center of the brain.
The implant runs on a battery that can be replaced every few years and can remain in a patient indefinitely. Many patients with implants have lived depression free since the first DBS operations performed over a decade ago. Prof. Mayberg said that recovery can be extremely dramatic in some patients, while it can take a year or maybe two in others. She said that in trials conducted by her and her colleagues, the recovery rate was around 75%.
She was of the opinion that just as correct tuning of the DBS causes Parkinsonian tremors to disappear, with the availability of increased mapping data, scientists can today precisely tune depression circuits in the brain to alleviate depression symptoms. Suggesting that treatment can be individualized with growing availability of brain image mapping data, Prof. Mayberg said that the emphasis on development of algorithms and biomarkers that will discriminate patient subgroups will optimize treatment selection for individual patients. She opined that SCC is not the only brain area being tested. Identifying which target is best for a given patient is the next step once the different targets now being studied are proven safe and effective in large scale clinical trials.
