Four studies in the August 2 JAMA have expanded the body of data showing that highly traumatic experiences can have both neuropsychological and mental health consequences. Two of the studies focused on war- related events in the Middle East, and the other two evaluated victims of the December 2004 tsunami in southern Thailand.

In one study involving 654 US Army personnel deployed to Iraq, Jennifer J. Vasterling, PhD, and colleagues found a greater risk of impairment on select measures of neuropsychological health in these soldiers following a tour of duty, compared with soldiers who were not deployed overseas. "Deployment seemed to be disadvantageous to memory and the ability to focus over time," said Dr. Vasterling, Clinical Associate Professor of Psychiatry and Neurology at Tulane University in New Orleans. "Deployed soldiers also reported feeling less sharp cognitively and feeling more tense. On the other hand, they were able to react more quickly."

The current risks of anxiety, depression, and posttraumatic stress disorder (PTSD) were greater among 153 Iranian civilians who were victims of conventional and/or chemical warfare during the Iran-Iraq War of 1980 to 1988, compared with those exposed to low-intensity conventional warfare, Farnoosh Hashemian, MPH, and colleagues reported. Those risks were also elevated, by about one half, in the two studies of Thai tsunami survivors.

EFFECT ON TROOPS IN IRAQ

The American soldiers in Dr. Vasterling’s study typically served in Iraq for 12 months between April 2003 and June 2005. "The most prevalent military occupational categories were infantry/gun crew (35%), communication/intelligence (19%), electrical/mechanical equipment repair (13%), and service supply (9%)," the authors reported.

The neuropsychological status of the soldiers before and after deployment was assessed with a battery of performance-based tests such as the Wechsler Memory Scale, Neurobehavioral Evaluation System, and Automated Neuropsychologic Assessment Metric subtests; on average, the soldiers’ second assessments took place 73.4 days after they returned to the US. Their results were compared with those of 307 similar soldiers who were on active duty during the study period but who were not deployed to Iraq.

The deployed soldiers "reported significant combat activity, even when assigned to support roles," stated the authors. "Frequently reported combat experiences included receiving hostile incoming small arms–type fire (98%), participating in a support convoy (95%), and going on combat patrols/missions (91%).... Numerous soldiers reported receiving hostile incoming fire (35%) or participating in a combat mission (49%) daily."

The percentages of soldiers who witnessed the serious wounding or killing of friendly or enemy soldiers were 55% and 61%, respectively. "Seeing people begging for food (98%), observing homes or villages destroyed (77%), and seeing Americans or allies after they had been severely wounded or disfigured in combat (63%) ranked among the most frequently reported of other potentially stressful war-zone events," added the authors.

At the first neuropsychological assessment, the study and comparison groups were similar in terms of demographics and relevant variables such as sleep, developmental disorders, and alcohol consumption. Measures of neurobehavioral and emotional status were similar in the two groups as well.

However, in multiple linear regression analysis, deployment to Iraq was associated with neuropsychological impairment on tasks of sustained attention, verbal learning, and visual-spatial memory and with increased levels of tension and confusion. The deployed soldiers displayed improved simple reaction time, a finding consistent with neurobiologic responses that facilitate survival in life-threatening circumstances.

"We might be seeing the remnants of what was probably a very adaptive survival response started in the war zone," Dr. Vasterling commented. "From a psychological perspective, it makes sense to devote cognitive resources toward reacting quickly under these circumstances. However, there might be a temporary price of directing cognitive resources away from trying to learn and remember new things."

It is unclear, though, whether the changes observed in the deployed soldiers are clinically significant, pointed out Matthew Hotopf, PhD, and Simon Wessely, FMedSci, in an editorial. "The authors emphasize that the neuropsychological changes are ‘mild’ and ‘subtle,’" Drs. Hotopf and Wessely stated. "Such shifts in a population’s neuropsychological function may not be discernible to the individual but may affect other health outcomes. For example, following the [first] Gulf War, there was an increase in accidental deaths." Dr. Hotopf is affiliated with the Institute of Psychiatry, and Dr. Wessely is affiliated with the King’s Centre for Military Health Research, both in London.

EFFECT ON IRANIAN CIVILIANS

The data reported by Ms. Hashemian’s group, however, left little doubt about the significance of the mental health effects of conventional and chemical warfare on the Iranian civilians studied. "There were devastating long-term adverse effects, and the extent of the damage was surprising considering the exposures occurred nearly two decades ago," stressed Ms. Hashemian, a Research Associate in the Department of Global Health at the Yale University School of Public Health in New Haven.

The authors evaluated three levels of exposure to warfare among the Iranian civilians during the Iran-Iraq War: low-intensity (living in an area that was bombed fewer than 10 times), high-intensity (residing where there were 60 to 75 bombings), and high-intensity plus a chemical weapons attack. Compared with those exposed to low-intensity warfare, those exposed to both high-intensity warfare and chemical weapons had an 18.6 greater risk for lifetime PTSD and a 27.4 greater risk for current PTSD. Exposure to high-intensity warfare but not to chemical weapons also raised the odds ratio for lifetime PTSD by 5.4 times, and by 4.3 times for current PTSD compared with exposure to low-intensity warfare.

"We hope that our study provides international visibility to the lasting mental health consequences of conventional and chemical attacks on civilians and the need for mental health services for the survivors," said Ms. Hashemian in an interview with NeuroPsychiatry Reviews.

TSUNAMI SURVIVORS

The two studies of Thai tsunami survivors were conducted by groups led by Frits van Griensven, PhD, and by Warunee Thienkrua, MSc, who are both affiliated with the Thailand Ministry of Public Health–US Centers for Disease Control and Prevention Collaboration. In the van Griensven study, several assessment tools were used to identify mental health problems among a random sample of 1,061 adult tsunami survivors, 371 of whom were displaced from their homes after the disaster. Thienkrua and colleagues evaluated 371 children, 167 of whom were displaced. In both studies, survivor assessments occurred at eight weeks and nine months after the tsunami.

The two studies "mark an impressive advance in the field of psychiatric epidemiology," commented Derrick Silove, MD, and Richard Bryant, PhD, in an editorial. "These studies demonstrate both the feasibility and value of undertaking rapid needs assessments to guide mental health planning after disasters." Drs. Silove and Bryant are both Professors at the University of New South Wales in Sydney.

"A critical question is whether survivors with early symptoms of PTSD, depression, and anxiety warrant psychological interventions, particularly the nonspecific counseling that commonly is offered in these settings," Drs. Silove and Bryant stated.

The collection of nine-month follow-up data is a rare achievement in the developing world, according to Drs. Silove and Bryant. Other strengths of these studies, they noted, are timeliness, the prominent role of Thai researchers, rigorous sampling methods, and the use of international and culture-specific indices of distress.

In addition, both studies provided useful prevalence estimates for tsunami-related PTSD, anxiety, and depression. For example, the rates of PTSD at eight weeks for the displaced and nondisplaced adults in the van Griensven study were 12% and 7%, respectively. The rates of anxiety and depression at that time were roughly two to three times greater. "If these values are extrapolated to the wider tsunami-affected region, the numbers [of persons] with PTSD symptoms would run into the several millions," Drs. Silove and Bryant estimated.

Although one might assume that these individuals require counseling and other psychological interventions, the best therapy may be to stabilize the social environment and enable survivors to resume their livelihoods. "In that respect, it is noteworthy that the [van Griensven study] found that loss of livelihood was an independent predictor of ongoing mental health problems," related Drs. Silove and Bryant.

While the adults studied showed large reductions in symptoms of PTSD, anxiety, and depression at nine months, those symptoms were little changed over time among the children in the Thienkrua study. That finding raises the question of whether the children continued to experience emotional isolation or grief related to the loss of parents. The study did not address this issue, however.

—Timothy Begany

Suggested Reading
Hashemian F, Khoshnood K, Desai MM, et al. Anxiety, depression, and posttraumatic stress in Iranian survivors of chemical warfare. JAMA. 2006;296:560-566.
Hotopf M, Wessely S. Neuropsychological changes following military service in Iraq: case proven, but what is the significance? JAMA. 2006;296:574-575.
Silove D, Bryant R. Rapid assessments of mental health needs after disasters. JAMA. 2006;296:576-578.
Thienkrua W, Cardozo BL, Chakkraband MLS, et al. Symptoms of posttraumatic stress disorder and depression among children in tsunami-affected areas in southern Thailand. JAMA. 2006;296:549-559.
van Griensven F, Chakkraband MLS, Thienkrua W, et al. Mental health problems among adults in tsunami-affected areas in southern Thailand. JAMA. 2006;296:537-548.
Vasterling JJ, Proctor SP, Amoroso P, et al. Neuropsychological outcomes of army personnel following deployment to the Iraq war. JAMA. 2006;296:519-529.

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