Neurocognitive studies attempt to understand the link between the brain on one hand; and thoughts, emotions and behaviour on the other. As such, the brain is studied at the level of brain regions and the networks of brain regions, and thus complements the cellular data obtained from post-mortem studies. Neurocognitive studies are also contextualised by clinical studies. A large number of studies have evidenced the existence of dysfunctional cognitive processes which are associated to a vulnerability to suicide, for example decision making and problem resolution processes. These deficits could represent factors associated to stress sensitivity, notably social. In stressful situations, they could increase the individual’s risk of experiencing feelings of despair, psychological pain, ruminations, suicidal ideation; and in certain cases, to commit suicide. It has been shown that these cognitive difficulties are associated to the dysfunction of particular brain regions such as the prefrontal cortex and other regions. The general objectives of the research are to improve the knowledge of these dysfunctional processes with the help of neuropsychology and functional neuroimaging (mainly MRI). Transcranial magnetic stimulation (TMS) is another interesting method to help us understand the function of the brain and also represents a novel therapeutic tool whose full potential is still being evaluated by our team.