**2.2 Procedures**

98 Post Traumatic Stress Disorders in a Global Context

Major depression is also highly prevalent in individuals injured in a motor vehicle accident. The prevalence of major depression as determined by structured clinical interviews ranges from 10–19% at 0–3 months after the accident (O'Donnell et al., 2004; Matsuoka et al., 2008; Shalev et al., 1998) to 10–14% at 4–12 months after it (O'Donnell et al., 2004; Shalev et al., 1998). Although many symptoms overlap between posttraumatic stress disorder and major depression, the high comorbidity cannot be explained solely by this (Franklin & Zimmerman, 2001). Exposure to traumatic events has been shown to be linked not only to posttraumatic stress disorder, but also to depression (Duncan et al., 1996; Kilpatrick et al., 1987), and a recent study suggested that traumatic experiences during young adulthood and middle age are strong predictors of anxiety and depression among older adults (Dulin & Passmore, 2010). The treatment of psychiatric morbidity after injury is thus a matter of some urgency, especially for high-risk individuals. However, as it is difficult for emergency department staff to screen patients early after the event using a conventional questionnairebased tool, given the large number of motor vehicle accident survivors they handle (Nishi et al., 2006), it is desirable to find indicators for posttraumatic stress disorder which can be

**1.1 Depression and other anxiety disorders after motor vehicle accidents** 

easily assessed in order to provide preventive strategies as early as possible.

Among the indicators for posttraumatic stress disorder, peritraumatic distress is a good candidate for screening individuals at high risk of developing the disorder. Peritraumatic stress can enhance trauma-related memory and sensitize the neurobiological systems (Charney et al., 1993), which links to the development of posttraumatic stress disorder. Many clinical studies and a meta-analysis have shown that perceived threat to life is a predictor of posttraumatic stress disorder (Holbrook et al., 2001; Matsuoka et al., 2008; Ozer et al., 2003; Schnyder, Moergeli, Trentz et al., 2001) and psychiatric morbidity (Matsuoka et al., 2008; Schnyder, Moergeli, Trentz et al., 2001). Peritraumatic distress is also linked with posttraumatic growth, which Tedeschi & Calhoun (2004) define as the positive psychological change experienced as a result of the struggle with highly challenging life circumstances. They state that only psychologically 'seismic' events shake the assumptive world, which leads to posttraumatic growth. Accordingly, peritraumatic distress can be an indicator for posttraumatic growth. A better understanding of peritraumatic distress would be significant for both prevention, especially in emergency settings, and treatment of

The aim of this chapter is to elucidate the predictive usefulness of peritraumatic distress and to examine the future directions for prevention with a focus on the use of the Peritraumatic

Participants were selected from the Tachikawa Cohort of Motor Vehicle Accidents study conducted at the National Disaster Medical Center in Tokyo, Japan (Matsuoka et al., 2009). The inclusion criteria in the present study were as follows: 1) motor vehicle accident-related severe physical injury causing a life-threatening or critical condition; 2) age between 18 and 69 years; and 3) native Japanese speaking ability. The exclusion criteria were the following:

**1.2 The importance of assessing peritraumatic distress** 

Distress Inventory, an assessment tool for peritraumatic distress.

posttraumatic stress disorder.

**2. Method** 

**2.1 Participants** 

The study protocol was approved by the Institutional Review Board and Ethics Committee of the National Disaster Medical Center. After providing a complete description of the study to the subjects, written informed consent was obtained from them. The median number of days between the motor vehicle accident and the initial assessment was 2 days (range, 0–23 days). The initial assessment was conducted after cognitive function was assessed by a trained research nurse or psychiatrist using the Mini Mental State Examination.

In a structured interview, data was collected on general socio-demographics, the motor vehicle accident in detail, injury severity score (Baker & O'Neill, 1976), Glasgow Coma Scale score (Teasdale & Jennett, 1974), status during the accident (e.g., vehicle driver), vital signs first recorded on admission to the emergency room, lifestyle, and family history of psychopathology. Also, the Peritraumatic Distress Inventory was conducted at initial assessment. Follow-up assessments were performed at 1 month (median, 37 days, range, 24- 76 days) and 18 months (median, 561.5 days, range, 442-700 days) after the accident. The Impact of Event Scale-Revised and the Hospital Anxiety and Depression Scale were conducted at 1 month post accident, and the Posttraumatic Growth Inventory was conducted at 18 month post accident. The participants were asked to visit the National Disaster Medical Center or to return the completed self-report questionnaires in a stampaddressed envelope. After each assessment, participants were given a gift voucher for their participation (1,000 JPY [12 USD]).

#### **2.3 Measures**

#### **2.3.1 The Peritraumatic Distress Inventory**

The Peritraumatic Distress Inventory is a 13-item self-report questionnaire which assesses not only any threat to life experienced but various emotional responses experienced during and immediately after a critical incident (Brunet et al., 2001). Responses are provided on a 5 point Likert scale ranging from 0 to 4 (0, not at all to 4, extremely true). It typically takes only several minutes to complete all of the items, meaning the Inventory can be used immediately after a motor vehicle accident.

Peritraumatic Distress in Accident Survivors: An Indicator for

quantified by the 95% confidence interval (95% CI).

stay (Baker & O'Neill, 1976).

for Windows (SPSS, Tokyo, Japan).

**3. Results** 

(range 0-40).

potential confounders.

I could not do more

Univariate regression analysis

Posttraumatic Stress, Depressive and Anxiety Symptoms, and Posttraumatic Growth 101

For the covariates, age at motor vehicle accident, being female, history of psychiatric illness, family history of psychopathology, and lower education level are well-established pretraumatic risk factors across trauma type (Brewin et al., 2000; Ozer et al., 2003). As for educational level, we used graduation from junior high school as a reference (0), and assigned 1 to graduation from high school, 2 to graduation from junior or technical college, and 3 to graduation from university or higher educational institutions according to the Japanese educational system. Heart rate on admission was selected because some reports in the literature on motor vehicle accident showed its association with posttraumatic stress disorder (Bryant et al., 2000; Shalev et al., 1998; Zatzick et al., 2005). Injury Severity Score divided into 10–point increments was assigned as the objective accident-related variable. Injury Severity Score is a scoring system that provides a total score for patients with multiple injuries, and it correlates with measures of severity such as mortality and hospital

Univariate regression analysis was also conducted to examine the relationships of total score on the Peritraumatic Distress Inventory with total score and individual subscale scores on the Posttraumatic Growth Inventory. Any association between the dependent variable and the independent variable was expressed as a regression coefficient (beta weight) and

All statistical analyses used two-tailed tests. Statistical significance was established at a P value < 0.05. All data analyses were performed using SPSS statistical software version 19.0J

Of the 130 patients participating, 79 (60.8%) attended the 1-month follow-up assessment and 51 (39.2%) attended the 18-month one. The patients who dropped out of the study did not differ significantly from those who participated in terms of the variables selected for

Of the 79 participants at first follow-up, 16 (20.3%) were women and median age was 37.0 years (mean, 39.7; range 18-69), and 7 (8.9%) reported a past history of psychiatric illness. Median ISS was 6.0 (range 1-41) and median Peritraumatic Distress Inventory score was 15.0

The relationships of total score and individual item scores on the Peritraumatic Distress Inventory with posttraumatic stress symptoms and depressive and anxiety symptoms are shown in Table 1. The Peritraumatic Distress Inventory was an independent predictor for posttraumatic stress symptoms and depressive and anxiety symptoms after adjusting for

1. I felt helpless to do more 4.00 (2.05, 5.94) <0.01 1.80 (0.86, 2.74) <0.01 2. I felt sadness and grief 3.05 (1.03, 5.06) <0.01 0.94 (-0.06, 1.93) 0.06 3. I felt frustrated or angry 2.99 (1.11, 4.87) <0.01 0.74(-0.20, 1.68) 0.12

Beta (95% CI) P Beta (95% CI) P

investigation in this study, including total Peritraumatic Distress Inventory score.

PDI item IES-R HADS

The original Peritraumatic Distress Inventory has been demonstrated to be internally consistent, stable over time, and with good to excellent correlations between item and total scores (Brunet et al., 2001). Moreover, it was found to be valid against posttraumatic symptoms and peritraumatic dissociation as assessed by the Impact of Event Scale-Revised and the civilian version of the Mississippi Scale for Combat-Related Posttraumatic Stress Disorder.

With the original authors' permission, we translated the original English Peritraumatic Distress Inventory into Japanese. We followed the standard procedure of back-translation. Namely, the first author (DN) translated the English version into Japanese. This preliminary Japanese version was then backtranslated into English by an independent translator. The backtranslated version was examined by the original authors. Then we corrected the Japanese translation accordingly. This process was repeated until both sets of authors agreed that the original and backtranslated versions matched closely. Subsequently, we verified the internal consistency, test-retest reliability, concurrent validity with measures of peritraumatic dissociation and posttraumatic symptoms, and divergent validity of the Japanese version of the Peritraumatic Distress Inventory (Nishi et al., 2009).
