Patients show severe fatigue, deep sadness, loss of pleasure and interest, a strong feeling of worthlessness along with great concentration difficulties. Unlike transient sadness episodes » the strong feeling of dejection « , major depressive episode (MDE) continues for more than 15 days without remission of mood despite outside influences. It can lead to isolation of the person or even to suicide.
Research has highlighted the existence of a genetic vulnerability, but it is the combination of risk factors such as situations or life events (death, unpleasant break-up, job loss, unhappy childhood…) and the occurrence of recurrent depressive episodes (relapses) which determine the degree of severity of the disease.
Today, many effective treatments exist to treat this pathology : chemical treatments (antidepressants) helping to relieve depressive symptoms, often associated with medical and psychotherapeutic support, and physical treatments such as deep electrical stimulation or electroconvulsive therapy (ECT, still called electroshocks today), therapeutic means used in most resilient forms.
Depression is the most common mental illness, since it is estimated that 5% to 15% of the French population is at risk of having a depressive episode during life. It is present at all ages.
Today, it is estimated that 3% of children are affected by this disease. This prevalence increases from 10 to 15% among adolescents and it is also important for the elderly.
This makes it a particularly severe condition since it is estimated that risk of death by suicide is 10 times higher for the depressed person than for the rest of the population. In France, there are 12 000 deaths by suicide each year, meaning a person dying by suicide every hour.
TOPICS AND RESEARCH TEAMS
Emotions, depression and social interaction : Nathalie George and Philippe Fossati’s team is interested in the mechanisms by which social processes activate and regulate the emotional brain. Accordingly, it is interested, among other things, in depression and autism.
Several research leads are under study. One of the first hypotheses approached is the inflammatory lead. Depression could be due to abnormal response of the inflammatory system or manifestation of a chronic inflammatory disease. Existence of a genetic predisposition is under study, which for the moment does not give convincing results. Finally, brain imaging works help to understand the brain disturbances involved in depression. For this reason, the Social and emotional Neuroscience team at the ICM is particularly interested in emotional dysfunction brain features and social disturbances involved in depressive illness. Today, by combining functional neuroimaging techniques and the development of behavioural and cognitive tests, the team wants to know how depressed patients emotionally or cognitively respond, by evaluating them in comparison to control or at risk subjects. The objective of this research is to identify biomarkers involved in depression. The overall research objective is to be able to combine all these aspects in order to propose more personalised treatments based on patients’ biological needs.
Quantitative assessment of apathy
Apathy, defined as a loss of motivation and interest, is a symptom frequently encountered in many pathologies such as depression, schizophrenia, but also Parkinson’s and Alzheimer’s diseases. Through the PRISM platform, an innovative project, EcoCapture, developed by Richard Levy aims to investigate apathy. Through body sensors, apathetic patients’ behaviours will be analysed in semi-ecological situation. The objective of this work is to use the collected data to put back to work people who have had a neurological deficit, with decision-making or behavioural disorders.
Identify biomarkers of depression
The issue of the ANR SENSO project, coordinated by Philippe Fossati is to define biological and brain imaging markers to facilitate the diagnosis of depression. To identify these markers, depressed patients’ brain activity (by functional Magnetic Resonance Imaging and EEG) and biological activity (markers of inflammation in blood) are measured. The results of this project should thus help to develop new therapeutic strategies, closer to patients’ difficulties. The definition of biological markers should enable to monitor more accurately the effects of these therapeutic interventions. The results of this project will contribute to the development of personalised medicine adapted to depressed patients’ specific needs.