The epidemiology of post-traumatic stress disorder in Norway: trauma characteristics and pre-existing psychiatric disorders

Eva Lassemo,Jan F Nygård,Inger Sandanger,Knut W Sørgaard

doi:10.1007/s00127-016-1295-3

Abstract

PurposeThe prevalence of PTSD differs by gender. Pre-existing psychiatric disorders and different traumas experienced by men and women may explain this. The aims of this study were to assess (1) incidence and prevalence of exposure to traumatic events and PTSD, (2) the effect of pre-existing psychiatric disorders prior to trauma on the risk for PTSD, and (3) the effect the characteristics of trauma have on the risk for PTSD. All stratified by gender.MethodCIDI was used to obtain diagnoses at the interview stage and retrospectively for the general population N = 1634.ResultsThe incidence for trauma was 466 and 641 per 100,000 PYs for women and men, respectively. The incidence of PTSD was 88 and 31 per 100,000 PYs. Twelve month and lifetime prevalence of PTSD was 1.7 and 4.3 %, respectively, for women, and 1.0 and 1.4 %, respectively, for men. Pre-existing psychiatric disorders were risk factors for PTSD, but only in women. Premeditated traumas were more harmful.ConclusionGender differences were observed regarding traumatic exposure and in the nature of traumas experienced and incidences of PTSD. Men experienced more traumas and less PTSD. Pre-existing psychiatric disorders were found to be risk factors for subsequent PTSD in women. However, while trauma happens to most, it only rarely leads to PTSD, and the most harmful traumas were premeditated ones. Primary prevention of PTSD is thus feasible, although secondary preventive efforts should be gender-specific.

Highlights

Disabling psychopathology attributable to distressing experiences is very old and has been referred to in the literature throughout time, albeit under different names
While trauma happens to most, it only rarely leads to Post-traumatic stress disorder (PTSD), and the most harmful traumas were premeditated ones
Proportion exposed to potentially traumatic events (PTEs)/with PTSD (%) Mean age at worst traumatic exposure Mean age at onset PTSD Mean years from worst traumatic exposure to PTSD Mean years of duration of PTSD Psychiatric disorder pre-existing to trauma and PTSD

Summary

Introduction

Disabling psychopathology attributable to distressing experiences is very old and has been referred to in the literature throughout time, albeit under different names. Descriptions of combat fatigue, which fit diagnostic criteria of the present day PTSD remarkably well, can be found in Greek and Norse literature, as well as in Shakespeare [1,2,3]. Exposure to potentially traumatic events (PTEs) is common [4, 5], yet only a fraction of people exposed ever meet the current diagnostic criteria for PTSD [6]. PTEs are events that may be perceived and experienced by the individual as lifethreatening or dangerous.

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Discussion

Conclusion