BackgroundPeople who witness a horrific event are at risk of suffering from acute psychological disorders, potentially leading to chronic post-traumatic symptoms and severe medico-psycho-social complications. Traumatised individuals suffer from psychological damage that is initially indescribable: they are often unable to ask for care in the immediate aftermath of an event. Afterwards, traumatic events and their post-traumatic consequences are still often hidden or minimised by patients for reasons linked to the disorder itself (inexpressibility, shame, depressive thoughts, fear of stigmatisation, etc.). The provision of the initial stage of care has a major impact on the long-term prognosis. Although official French recommendations remain vague, and scientific studies lack power, there is a developing professional consensus on practices, and developments in neurobiology are opening up new opportunities to validate them. ObjectiveDrawing upon our clinical experience and clinical principles provided by our mentors, our aim is to clarify the phases of psychotherapeutic treatment, and we describe three practices: immediate care (“defusing”), post-immediate care (“French debriefing” or “post-immediate psychotherapeutic intervention”) and follow-up care (“deferred debriefing” and psychotherapy). Although the international literature considers these phases as separate, here we describe a continuity of talking therapies that support long-term remission. ResultsThe effectiveness of the combination of immediate, post-immediate and follow-up care has been confirmed by events surrounding the recent Paris and Nice attacks. Specific psychotherapeutic principles are unrelated to a particular school of psychotherapy (notably cognitive and behavioural therapies, analytical therapies, various forms of hypnosis, and eye-movement therapies, etc.). Instead, they refer to specific principles that are effective in the treatment of post-traumatic psychiatric disorders. By helping the individual to verbalise their experience, talking re-establishes dissociated psychological functions. A process of reconsolidation enables sensory memory to be integrated into verbal memory. Supported by psychotherapy, language can be used to discover, or construct, a new sense of meaning for the individual. ConclusionA single session of post-immediate or deferred debriefing has been found to have a miraculous effect on post-traumatic symptoms, confirmed by follow-up. When disorders are chronic and complex, however, treatment can last several months or years. In each case, although certain therapeutic principles are key, other psychotherapeutic and pharmacological treatments should be adapted to the individual's clinical situation, and the symptoms they present.