Posttraumatic stress disorder after motor vehicle accidents: 3-year follow-up of a prospective longitudinal study

Abstract

The paper presents a 3-year follow-up of a prospective longitudinal study of posttraumatic stress disorder (PTSD) after motor vehicle accidents (J. Abnormal Psychol., 107 (1998) 508). Participants were 546 patients who had been assessed when attending an emergency clinic shortly after a motor vehicle accident, and at 3 months and 1 year afterwards. The prevalence of posttraumatic stress disorder PTSD at 3 years was 11%. Maintaining psychological factors, i.e. negative interpretation of intrusions, rumination, thought suppression and anger cognitions, were important in predicting the persistence of PTSD at 3 years, as were persistent health and financial problems after the accident. Other predictors were female sex, hospital admission for injuries, perceived threat and dissociation during the accident, and litigation.

Introduction

Many people experience at least some of the symptoms of posttraumatic stress disorder (PTSD) in the immediate aftermath of traumatic events such as assault, natural disasters, or motor vehicle accidents. A sizeable proportion recover in the next few weeks or months, but in a significant subgroup the symptoms persist, often for years (Kessler, Sonnega, Bromet, Hughes, & Nelson, 1995). It is largely the subgroup of people with persistent PTSD who seek treatment.

Despite the substantial rate of recovery from PTSD in the first year after trauma, PTSD research has to date largely focused on the question of which factors determine whether an individual will develop PTSD after a traumatic event. Variables such as aspects of trauma severity, the individual's emotional response during the trauma, sex, pre-trauma personality and history of psychiatric disorders have been linked to the onset of PTSD (for reviews see Blanchard & Hickling, 1997; Ehlers, Mayou, & Bryant, 1998). However, these variables only explain a small proportion of the variance of chronic PTSD.

Several authors have argued that maintaining factors need to be taken into account in addition to those explaining PTSD onset (Ehlers & Clark, 2000; Ehlers & Steil, 1995; Foa & Riggs, 1993; Foa & Rothbaum, 1998). This hypothesis is supported by a recent large-scale prospective study of consecutive patients who attended an accident and emergency clinic after a motor vehicle accident (MVA). The study demonstrated that the accuracy in predicting PTSD symptoms at 1 year could be substantially enhanced if psychological maintaining factors derived from theoretical considerations (Ehlers & Steil, 1995) were taken into account, i.e. negative interpretation of intrusive memories, rumination, thought suppression, and anger (Ehlers et al., 1998). The prognostic power of these variables compared favorably with that of variables shown to be related to PTSD severity after MVA in previous studies, i.e. trauma severity, pre-accident psychological and social variables, emotional response during the trauma, and litigation (Blanchard et al., 1996a, Blanchard et al., 1996b).

Ehlers et al. (1998) also found, in line with previous findings (Blanchard et al., 1997; Mayou, Bryant, & Duthie, 1993; Mayou, Tyndel, & Bryant, 1997), that persistent health problems and financial problems resulting from the accident were more closely related to PTSD at 1 year than initial injury severity, again supporting the role of maintaining factors.

The present paper presents a 3-year follow-up of participants described by Ehlers et al. (1998). Our aims were to:

• Determine the prevalence of PTSD at 3 years after a MVA.

• Investigate the contribution of maintaining variables measured at 3 months and 1 year in predicting PTSD symptoms at 3 years.