Predictors of posttraumatic stress among victims of motor vehicle accidents

OBJECTIVE

This study identified factors that predict individual vulnerability to psychological trauma by examining the relationships among situation and person variables and symptoms of posttraumatic stress disorder (PTSD) 1, 6, and 12 months after a serious motor vehicle accident (MVA).

METHODS

Background characteristics, exposure variables (ie, injury severity and accident characteristics), and psychosocial variables (ie, perceived loss of control, social support, and coping) were used to predict symptoms of PTSD and recovery in 115 injured MVA victims. All participants were injured during the MVA and provided data prospectively over the course of a year after their accidents.

RESULTS

Along with background and exposure variables, use of wishful thinking coping distinguished between victims with and without symptoms of PTSD.

CONCLUSIONS

Psychosocial variables such as wishful thinking coping can be used to identify MVA victims who are at risk of developing chronic posttraumatic stress and warrant further investigation.

Similarity of prior trauma exposure as a determinant of chronic stress responding to an airline disaster

The cumulative effects of trauma were examined in 108 workers at the site of a major air disaster at 4 time points over a year following the crash. The influence of trauma history on chronic distress and physiological arousal associated with the crash were examined. Stress levels were expected to differ on the basis of the similarity of prior trauma exposure to work at the crash site. Prior traumatic exposure that was "dissimilar" to this type of work was associated with greater vulnerability to crash-related stress, that is, more distress and crash-related intrusions during the year following the crash. Accumulation of a variety of different traumatic experiences appeared to sensitize workers to the new stressor and to perpetuate chronic stress. Understanding the role of trauma history is important for improving intervention efforts aimed at alleviating stress following a trauma.

Urinary catecholamines and cortisol in recent-onset posttraumatic stress disorder after motor vehicle accidents

OBJECTIVE

This study examined relationships among stress hormone levels, posttraumatic stress disorder (PTSD) diagnosis and symptoms, and gender shortly after a common civilian trauma.

METHODS

Levels of catecholamines and cortisol in 15-hour urine samples were examined in 55 adults who had been in serious motor vehicle accidents and in 22 age-matched control.

RESULTS

Catecholamines were related to PTSD diagnosis and symptoms, but only among men: PTSD-symptomatic men who had been in an accident exhibited elevated levels of epinephrine and norepinephrine 1 month after the accident and had higher epinephrine levels 5 months later. Intrusive thoughts predicted catecholamine levels at 1 month, and avoidance of trauma-relevant stimuli was associated with higher epinephrine levels 5 months later. These effects were not significant among women. Urinary cortisol was also elevated among PTSD-symptomatic men, but not women, and only immediately (1 month) after the accident. For men and women, greater emotional numbing predicted a lower cortisol level 6 months after the accident.

CONCLUSIONS

These findings were interpreted as limited support for the generalizability of findings in men with chronic, combat-related PTSD and indicate the need for additional research on psychoendocrine assessment of traumatized women and specific dimensions of PTSD symptomatology.

Similarity of prior trauma exposure as a determinant of chronic stress responding to an airline disaster

The cumulative effects of trauma were examined in 108 workers at the site of a major air disaster at 4 time points over a year following the crash. The influence of trauma history on chronic distress and physiological arousal associated with the crash were examined. Stress levels were expected to differ on the basis of the similarity of prior trauma exposure to work at the crash site. Prior traumatic exposure that was "dissimilar" to this type of work was associated with greater vulnerability to crash-related stress, that is, more distress and crash-related intrusions during the year following the crash. Accumulation of a variety of different traumatic experiences appeared to sensitize workers to the new stressor and to perpetuate chronic stress. Understanding the role of trauma history is important for improving intervention efforts aimed at alleviating stress following a trauma.

Cues, frequency, and the disturbing nature of intrusive thoughts: patterns seen in rescue workers after the crash of Flight 427

Intrusive thoughts have been identified as key elements of chronic or traumatic stress, but many questions remain about how they operate and what causes persistence of disturbing intrusions. The present study considers these questions, examining the impact of having intrusive thoughts that are cued by stimuli in one's environment as opposed to uncued intrusions that seem to "come out of the blue." In addition, this research evaluates the extent to which distress accompanying intrusive thoughts shortly after a traumatic event predicts persistence of intrusions over time. Rescue workers who responded to the crash of Flight 427 were studied 4 to 8 weeks, and 6, 9, and 12 months after the disaster. Participants who reported crash-related thoughts that were not prompted by cues showed higher levels of distress than those reporting only cued thoughts or those reporting neither. The magnitude of distress that these thoughts caused in the first 2 months after the crash was important in predicting subsequent frequency of unwanted thoughts. The presence or absence of cues and their role in the maintenance of distress also is discussed.

Acute and chronic posttraumatic stress disorder in motor vehicle accident victims

OBJECTIVE

This study reports the rates of acute and chronic posttraumatic stress disorder (PTSD) in a suburban community study group of 122 victims of serious motor vehicle accidents and a comparison group of 42 (who had been involved in minor, non-motor-vehicle accidents) followed over 12 months.

METHOD

Motor vehicle accident victims were systematically recruited and examined with comparison subjects at 1, 3, 6, 9, and 12 months after the accident. The authors used the Structured Clinical Interview for DSM-III-R to assess DSM-III-R axis I disorders including PTSD.

RESULTS

One month after the accident, 34.4% of the motor vehicle accident victims met criteria for PTSD (versus 2.4% of the comparison subjects). Similarly, at 3 and 6 months, rates of PTSD were higher (25.2% and 18.2%) in the motor vehicle accident victims than in the comparison group. Female victims were 4.64 times more likely than male victims to have PTSD at 1 month. Victims with a history of PTSD were 8.02 times more likely at 1 month and 6.81 times more likely at 3 months to have PTSD than those without a history of PTSD. Having an axis II disorder increased the risk for PTSD at 6 months. After adjustment for a history of PTSD and potentially confounding variables, women were 4.39 times more likely than men to develop PTSD at 1 month but did not have a higher risk for chronic PTSD; at 6 months, those with an axis II disorder were at greater risk of PTSD.

CONCLUSIONS

Rates of PTSD are high in victims of serious motor vehicle accidents and remain high 9 months later. Female victims have an increased risk of acute but not chronic PTSD. Individuals with a history of PTSD are at risk of acute and chronic PTSD. An axis II disorder increases the risk for chronic but not acute PTSD.

Assessment of characteristics of intrusive thoughts and their impact on distress among victims of traumatic events

OBJECTIVE

This study examines the psychometric properties of the Intrusive Thoughts Questionnaire (ITQ) and its utility as a predictor of distress among trauma victims.

METHOD

Victims of three types of trauma, a motor vehicle accident (N = 115), a hurricane (N = 182), and recovery work after an airline disaster (N = 159), completed the ITQ along with the Impact of Event Scale (IES) and the Symptom Checklist-90, Revised (SCL-90-R), at several different time points after their exposure.

RESULTS

The ITQ was a reliable and valid instrument that was positively related to concurrent measures of distress as well as a predictor of long-term stress responding. Characteristics of intrusive thoughts reflecting the extent to which they were unwanted or controllable, were identified as key determinants of distress.

CONCLUSIONS

The ITQ is a useful adjunct to current measures of intrusions, allowing for greater specificity in analyses of responses to trauma. Evaluation of characteristics of intrusions indicated that frequency of intrusions was neither the only predictor of distress nor the best predictor of trauma-related outcomes.

Responses of natural killer cell activity to acute laboratory stressors in healthy men at different times of day

To assess possible diurnal variations in natural killer reactivity to acute laboratory stressors, this study investigated changes in natural killer cell activity (NKCA) during and after three stressors (mental arithmetic, speech, and the Stroop) at 3 times of the day (08:00, 12:00, and 16:00) in 30 healthy men. NKCA activity increased during mental arithmetic and speech tasks at all 3 times of the day. Change in NKCA was greatest in the afternoon. Differences in the magnitude of mood changes were also observed at the 3 times of day, parallel to immune reactivity. These findings suggest that the dynamics of stress-related NKCA are more complex than previously believed and that time of day may affect the way they are generated or interpreted.

Responses of natural killer cell activity to acute laboratory stressors in healthy men at different times of day

To assess possible diurnal variations in natural killer reactivity to acute laboratory stressors, this study investigated changes in natural killer cell activity (NKCA) during and after three stressors (mental arithmetic, speech, and the Stroop) at 3 times of the day (08:00, 12:00, and 16:00) in 30 healthy men. NKCA activity increased during mental arithmetic and speech tasks at all 3 times of the day. Change in NKCA was greatest in the afternoon. Differences in the magnitude of mood changes were also observed at the 3 times of day, parallel to immune reactivity. These findings suggest that the dynamics of stress-related NKCA are more complex than previously believed and that time of day may affect the way they are generated or interpreted.

Chronic stress and natural killer cell activity after exposure to traumatic death

OBJECTIVE

The present study examined the effects of working at the crash site of USAir Flight 427 on psychological, cardiovascular, and immunological sequelae of stress within 2 months of the recovery work and again 6 months after the crash.

METHOD

A total of 159 workers at the crash site and 41 controls were examined within 2 months of the crash and again 6 months after the crash. Subjects were initially grouped according to whether they had contact with human remains. For a finer-grained analysis of exposure to bodies, subjects were also grouped by degree of exposure, determined by the area in which the workers were stationed. Dependent measures included intrusive thoughts, coping styles, and symptom reporting, as well as heart rate and blood pressure, and NK cell number and activity.

RESULTS

Workers exposed to body parts at the actual crash site, and those who were exposed to remains without expecting to be, exhibited more symptoms of stress than workers who saw bodies and body parts at the morgue and those who did not see human remains. Non-morgue workers who were exposed to bodies or body parts had the highest levels of intrusive thoughts at both time points, and the highest NK cell activity at Time 1. NK activity in this group decreased to levels comparable with other groups at Time 2.

CONCLUSIONS

Increased NK activity is unusual in chronic stress situations, and may be because of acute stress experienced as a result of being asked to talk and think about the crash. The finding that the more one was exposed to human remains the less distress he or she reported is discussed in terms of adaptation, expectancy, and control.

Time course of natural killer cell activity and lymphocyte proliferation in response to two acute stressors in healthy men

To clarify the time course of immune system activity during and after acute stressor exposure, this study collected immune measures from 31 men at 6 times (before, during, and after 2 common laboratory stressors; mental arithmetic with harassment or a cold pressor task). The 6-min stressor period was associated with increased self-report of pain and distress in both stressor groups and with increased systolic and diastolic blood pressure and heart rate in the mental arithmetic group. Increased natural killer cell activity in this group was observed during the task (2 and 5 min into the task) and 5 min after the task ended. A significant Group x Time effect was observed for lymphocyte proliferation to pokeweed mitogen, and a significant Group x Time x Dilution effect was observed for proliferation to concanavalin A. Inspection of the data suggested that this interaction was due to a reduction in proliferation in both stressor groups during the task period.