It has been shown in the literature that the symptoms of post-traumatic stress disorder influence the quality of life of patients, in particular through the cognitive alterations they can cause. Social cognition is also itself impacted. It refers to the perception, interpretation and processing of information relating to the social environment and relationships. It is affected by the symptomatology of PTSD both in terms of the response to emotional stimuli, the perception of self and others, and the quality of intimate relationships. These elements lead to reflection on the origin of these alterations, in particular the impact of PTSD on the patient's empathy capacity, defined as the recognition and understanding of the feelings and emotions of another individual. This parameter is also little studied in the literature, only a study dating from 2010 finds a correlation between PTSD and empathy. It is in this context that the realization of a new study studying the capacity for empathy of patients with PTSD in comparison with a control group with a larger and more representative population was envisaged. The primary outcome of this study is to analyze the post-traumatic stress disorder's repercussions on empathy by passing the Interpersonal Reactivity Index (IRI) on patients in comparison with a control group. The first hypothesis is a lower total score but a higher personal distress sub-score in the PTSD population. The secondary outcomes are to describe the cofactors that can influence empathy in association or not with post-traumatic stress disorder: sociodemographic data (age, sex, education level…), traumatic event type determined through the "Inventory of Traumatogenic Events", human intervention, duration and severity of the disorder (evaluated by the Impact of Events Scale) … The number of subjects required was calculated at 19 patients and 19 controls.

Any patient or controls who score positively off the diagnostic criteria for comorbidities such as major depressive episode, generalized anxiety disorder, psychotic disorder and autism spectrum disorder are not included. These criteria will be assessed through the MINI diagnostic interview and the Autism Spectrum Quotient.

The patients included will be followed at the Hospital of Nice for post-traumatic stress disorder diagnosed according to the DSM-V criteria. They are volunteers, adults, French speakers. The control population will be randomly selected (advertising, social networks…), adults and French speakers too, having no follow-up or current psychiatric treatment.