Susan Jeffrey

May 20, 2015

TORONTO — Almost 20 years after the Oklahoma City terrorist bombing that shook the nation in 1995, survivors report more depression and anxiety than controls, and almost a quarter of them report symptoms that would meet criteria for post-traumatic stress disorder (PTSD), a new study shows.

Researchers were led by Phebe Tucker, MD, professor, vice chair of education, and Arnold and Bess Ungerman Endowed Chair of Psychiatry in the Department of Psychiatry and Behavioral Sciences at the University of Oklahoma Health Sciences Center in Oklahoma City, who has cared for many of these survivors since the attack.

"Most of our survivors reported positive growth, and I think that that was important," Dr Tucker said at a press conference here. "But in summary, we felt this study showed that there are still unmet medical and psychiatric needs in some of our survivors, suggesting that additional recovery efforts should be extended beyond the 18 months or so they usually are and when we do help survivors that we should enhance the positive coping techniques that we've identified."

The results were presented here at the American Psychiatric Association (APA) 168th Annual Meeting.

20th Anniversary

The 20th anniversary of the attack was commemorated on April 19, 2015. On a bright morning, a truck bomb blew up in front of the Alfred P. Murrah Federal Building, killing 168 people, many of them children, and injuring 680 others. Until the attacks of 9/11, it was the deadliest terrorist attack on US soil.

"As the 20th anniversary was approaching, my research partners and I wanted to look at what happens to people long term, very long term, after they had been exposed to terrorism," Dr Tucker said. "So we looked at directly, intensely impacted individuals to assess their mental health and health status, and their post-traumatic growth over that period of time."

Included in this analysis were 138 direct survivors of the bombing, more than 80% of whom had been injured by the blast.

"We were lucky that the State Department of Health maintained a registry of individuals who were injured and who had agreed to participate in research many years ago," she noted.

Their responses were compared with those of 171 community members who were demographically similar but who were not directly or indirectly exposed.

All participants responded to a telephone survey, in which researchers used various questionnaires to assess physical and mental health status. Major medical and mental health problems were assessed by using the Health Status Questionnaire-12, healthcare utilization and alcohol use using Medical Status Questions, levels of depression and anxiety using the Hopkins Symptom Checklist, PTSD symptoms using Breslau's PTSD screen, and the Post-Traumatic Growth Inventory, "which is very important to measure resilience and recovery," Dr Tucker noted.

The two groups were then compared by using multivariable logistic regression and linear modeling. The groups were similar in sex, age, and ethnicity, but education levels were higher in survivors than controls, and more of the survivors were married or cohabitating, she said.

They found that anxiety and depression scales were elevated, she said, and were "higher in our survivors than controls almost 20 years later."

Results of the PTSD screen indicated that 23% of survivors reached the threshold for having PTSD. The Breslau scale, she noted, "is not a diagnostic rating scale, but achieving a score of 4 or more is very consistent with having PTSD."

Alcohol intake did not differ between survivors and controls for many measures, including binge drinking (defined as five or more units of alcohol at a sitting). However, the survivors did drink more; they had at least one drink on more days per week and more days per month than controls.

Binge drinking among survivors was also associated with higher levels of depression and anxiety, Dr Tucker noted. "So I think when we're assessing trauma survivors or terrorism survivors over the years, we want to look at those individuals who are more symptomatic with depression and anxiety and screen them for alcohol use problems, because this may be a way that they're coping with their memories."

They didn't see any difference in tobacco use, but she said, "I think we're number 4 in frequency of tobacco use in Oklahoma so it's kind of hard to find differences there."

The researchers had anticipated that many survivors would experience medical problems, but their results showed no significant difference in major medical problems between survivors and controls almost 20 years later. However, more than 60% of survivors reported worsened hearing after exposure to the bombing; about one third of this group were actually in the building and the remainder were directly outside the building or in nearby buildings, she said.

In terms of medical care use, survivors and controls did not differ in using mental health professionals in the last month, but survivors did receive more treatment from ancillary health services, such as physical therapists, speech therapists, and respiratory and occupational therapists. "We thought that that might reflect actual treatment for bombing-related injuries," she noted.

The researchers don't yet have death statistics from the Department of Health, but they plan to look at how many survivors have died since the bombing and compare that number to community rates.

Finally, the post-traumatic growth inventory is an important measure that looks at how people report positive change after having a significant, negative stressful experience, Dr Tucker said. "And if we look at our survivors who reported positive change to a great or very great degree, we see several areas rated very highly."

Among the statements that respondents agreed had changed for them to a great or very great degree was "people are wonderful." "There was a lot of social support after the bombing actually, people really pitched in," she said.

Other statements rated as positive change included "valuing life," "feeling stronger than one thought," and "understanding spiritual matters better," although the researchers didn't tease out differences between spirituality and organized religion. "Better handling of difficulty" was also ranked highly among the survivors.

First-Hand Experience

Jeffrey Borenstein, MD, president and CEO of the Brain and Behavior Research Foundation in New York City and chair of the American Psychiatric Association's Council on Communications, moderated the press conference here.

"Unfortunately now more and more people have first-hand experience of terrorism, both in the United States and around the world," Dr Borenstein said. "This research looked at survivors of the Oklahoma City bombing 20 years ago to determine how their mental and physical health was changed by that event. Dr Tucker has conducted and published research in areas including post-traumatic stress disorder, anxiety disorders, and the Oklahoma City bombing, and she has cared for survivors of the bombing for 20 years."

Asked to comment on these findings, JoAnn Difede, PhD, director of the Program for Anxiety and Traumatic Stress Studies at New York-Presbyterian/Weill Cornell Medical Center, said the study design was "reasonable" under the circumstances.

"Keep in mind that after a disaster, you don't have the luxury of creating a randomized, controlled clinical trial, so using matched controls makes sense, and in fact, it's an improvement on a lot of disaster research in that typically people reported their findings without comparing them to a comparable non-exposed group," Dr Difede told Medscape Medical News.

Overall the finding of higher depression and anxiety among the survivors isn't surprising. "When you think about what happened, and the nature of trauma, that makes sense, because even for people who get evidence-based treatment and improve substantially, and can go into remission, there are still anniversary reactions to the occasion, there are reminders out in the world about what happened to them, new terrorist attacks and what have you, so it's not a surprise at all actually."

Also not surprising but worth documenting was the positive growth among survivors, Dr Difede added. "It's an interesting finding that also bears some consideration in that while we know there are high rates of post-traumatic stress, anxiety, and depression, a substantial number of people find a way to go on and reorder their priorities in light of what happened to them so I think it's important that that finding be reported."

American Psychiatric Association (APA) 168th Annual Meeting. Abstract P8-133. Presented May 17, 2015.


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