Natural disasters, conflicts, persecution, population displacement, often traumatic migration experiences, and terrorist attacks are all factors that currently expose a significant proportion of the world's population to potentially traumatic events (PTEs). When a person is exposed to a PTE, symptoms of acute stress disorder (ASD) may occur in the immediate aftermath of the PTB, i.e., within the month following the event. These symptoms are dominated by dissociation, which includes depersonalization, i.e., the feeling of being disconnected from one's body. Managing these symptoms can prevent the subsequent onset of post-traumatic stress disorder (PTSD), a serious illness and public health concern. The recommended treatment combines an immediate post-event psychotherapeutic intervention (IPPI) and, where appropriate, medication with anxiolytics from the antihistamine class or antipsychotics