They are the leading cause of disability in France and affect one in five people in their lifetime. However, only 2% of the biomedical research budget is devoted to it. Still too often considered shameful, mental illnesses remain the poor relatives of medicine. One of the major challenges linked to these pathologies is the development of better treatments, whether they are preventive or curative.
For four years, the Marcel Dassault Prize has rewarded researchers who advance the fight against mental disorders. In December 2015, this distinction rewarded two researchers for their original and promising work: Doctor Laurent Groc, CNRS research director at the Interdisciplinary Institute of Neurosciences (University of Bordeaux), for his research on the causes of psychotic disorders, and Professor Philip Gorwood, head of department at Sainte Anne Hospital and professor at Paris Descartes University, who has worked on the importance of genes involved in addictive behaviors. Their studies help to better understand the molecular, genetic and cellular functions of these diseases in order to develop new and more effective treatments.
Acting on the immune system to treat schizophrenia
Psychotic disorders are due to interactions between genetic and environmental factors. What about one of the most well-known psychotic disorders, schizophrenia ? Precisely, it is by seeking to know more about the origins of this disease which affects 600,000 people in France (according to theInserm) that Dr. Laurent Groc has demonstrated the existence of a link between schizophrenic disorder and dysfunction of the immune system. Indeed, he noticed that schizophrenic patients have a high level of autoantibodies, molecules made by the body and which destroy the immune system, as if the latter were turning against itself. But to what extent are these autoantibodies linked to schizophrenia? In fact, according to his hypotheses, they modify the functioning of the cerebral circuits and cause delusions, hallucinationsand psychological disabilities.
Ultimately, the goal of the work of Dr. Groc’s team is to detect immune system dysfunctions as early as possible, for example by identifying specific markers in the blood of patients. “There is an urgent need to develop innovative therapeutic strategies in the field of mental illnesses such as psychotic disorders. It begins with the search for biological markers in psychotic patients that will allow individual treatment of appropriate treatment.“explains Laurent Groc. These treatments could, for example, consist in blocking the action of autoantibodies.
Regulate vulnerability genes to treat addictions
Another mental illness in need of treatment: addictive behavior of all kinds. Here again, genetics would be involved in many cases since several studies have shown that there is a vulnerability to addictions of genetic origin. And for Professor Philippe Gorwood, the study of the mechanisms (molecular and cellular) involved in addictions gives hope for the development of treatments. The idea would be to act directly on these genes to limit or cure addictions.
And one of the genes of particular interest to the researcher is the one that makes it possible to manufacture dopamine, the reward hormone released in large quantities by addictive substances. By reducing the amount of dopamine secreted in the brain of an addict (when he smokes, drinks alcohol or uses drugs), it would be possible to reduce addiction and therefore facilitate withdrawal.
A convincing example is that of the discovery of a group of vulnerability genes for tobacco addiction. This grouping is in fact associated in 14% of cases with tobacco dependence and an increased risk of lung cancer. Acting on the expression of these genes would help people who want to stop smoking and who struggle to achieve it.
At the same time, this genetic track has predictive power: detecting the presence of such genes would effectively prevent the risk of dependence even before it occurs. This process will require, according to Philip Gorwood, a close collaboration with sociologists and psychologists to find the best way to deliver the message and to pass the preventive information to the people concerned. Ultimately, this type of genetic screening could extend to other mental pathologies “for which the vulnerability genes involved will undoubtedly be discovered“, assures Professor Gorwood.
Source: Press conference for the Marcel Dassault Prize, awarded by the FondaMental foundation and the Dassault group, September 7, 2015.
>> To read also:
Schizophrenia: a game would improve patients’ lives
Creativity and mental illnesses have common genetic roots
Alcohol dependence: patients and doctors regret insufficient care
Are lefties more psychotic?
