Severity, timing, and duration of reactions to trauma in the population: an example from Mexico.

Normative data describing acute reactions to trauma are few. Of 2509 Mexican adults interviewed with the Composite International Diagnostic Interview, 1241 met trauma exposure criteria for index events occurring more than 1 year previously. The modal response, describing 45%, was a reaction to trauma that was mild (present but below levels of posttraumatic stress disorder symptom criteria), immediate (within the first month), and transient (over within a year). Nonetheless, 29% experienced immediate and serious reactions. Of these, 44% had chronic posttraumatic stress disorder symptoms. Those whose reactions were serious and chronic differed in many ways from those whose reactions were serious but transient. They had more traumatic events during their lives, and their index events were more likely to have occurred in childhood and to have involved violence. They had more symptoms and functional impairment after the trauma and higher levels of depressive and somatic symptoms when data were collected. Psychiatrically significant reactions to trauma persist often enough to justify their detection and treatment. Persons in need of acute intervention can be identified on the basis of the nature and severity of the initial response as well as characteristics of the stressor.