Deep Brain Stimulation for Neuropsychiatric Disorders: Current Status and Perspectives

Deep brain stimulation (DBS) is an established treatment for determined neurological disorders as Parkinson’s Disease, tremor and dystonia. Its safety and effectiveness encouraged researchers in recent years to propose to expand the technique for refractory and severe psychiatric disorders and other neurological diseases such as depression, obsessive-compulsive disorder, Gilles de la Tourette Syndrome, drug addition, aggressive behavior, eating disorders, post-traumatic stress disorder, anxiety and Alzheimer’s disease, for example. In this context, there is still much to be uncovered regarding anatomical targets, mechanisms of action, criteria for indication and exclusion of patients, and short term and long-term outcomes of such procedures. For all current indications, DBS aims to improve function, reduce symptoms and improve the quality of life of the patients and its caregivers, instead of providing cure. In this sense, DBS can be viewed as a neurorehabilitative technique. DBS is generally proposed for severe illnesses, when optimal clinical treatment and rehabilitation are not able to ensure adequate symptomatic relief and integration to society.

Although several reports have described the effects of DBS at various targets and for multiple neuropsychiatric indications, these data in general are derived from small open-label studies without control groups. A few examples of encouraging results include:

- Positive responses in reducing compulsive behavior with increase in global functioning in treatment-refractory OCD patients;
- Reducing depression severity in treatment resistant depression;
- Reduction of disruptive aggressive behavior with reintegration of patients to society;
-Benefits of DBS for nicotine addiction and alcoholism, reducing likelihood of relapse;
-Potential benefit of fornical/hypothalamic DBS in Alzheimer’s Disease patients;
-Potential efficacy of GPi or thalamic DBS for treatment-refractory Tourette’s syndrome;
-Potential benefit of hypothalamic DBS in controlling eating disorders.

Despite encouraging, the clinical results are considered preliminary and the underlying mechanism of action often remain obscure. Therefore, in this Research Topic, we aim to shed light in those diverse controversial aspects of DBS for neuropsychiatric indications.

The main question we want to answer in this Research Topic is: Is DBS better than optimal clinical treatment and rehabilitation for neuropsychiatric diseases? Other aspects to be included are:
· What structures or networks should we target for each specific disease? Include detailed anatomical descriptions of current and new targets, with possible mechanisms of action;
· Use of neuroimaging techniques such as DTI, fMRI and PET to unravel anatomical and functional localization of targets, change of functional imaging patterns before and after stimulation related to clinical findings;
· Evidences of efficacy of DBS for each specific disease, through double- blinded, randomized sham-controlled crossover trials; comparison of results of the stimulation of different anatomical structures.


We would like to acknowledge that Dr. Luis Eduardo Coutinho Castelo-Branco, Spaulding Rehabilitation Hospital, Boston, USA, has acted as a coordinator and has contributed to the preparation of the proposal for this Research Topic.

_{Topic Editor William Omar Contreras is the president OF INS Colombia, and CEO of the International Neuromodulation Center (NEMOD) in Bucaramanga, Colombia. The other Topic Editors declare no competing interests with regard to the Research Topic subject.}