Decoding Crisis: The Epidemiology of Disaster

Carol S. North, MD

Professor, Crisis Psychiatry, University of Texas Southwestern Medical Center, Director, Program in Trauma and Disaster, VA North Texas Health Care System

This interview was conducted by Peter Cook on June 1, 2006.

Introduction

In recent years, the United States has been subjected to disasters—both natural and man-made—of striking magnitude and far-reaching effect. While preventing future disasters is essential, the importance of understanding the effects of crises, and knowing how to properly deal with them, cannot be understated. When it comes to the psychiatric fallout of disaster, few have the knowledge and expertise of Dr. Carol North. Recently appointed chair of the newly minted division of crisis psychiatry at UT Southwestern Medical School, Dr. North has been in the field for close to 20 years. “I’ve been very involved in research,” she says, “in trying to understand, in a systematic way, what happens to people after all kinds of disasters.” She is also director of the program in trauma and disaster at the VA North Texas Health Care System, and has developed post-disaster mental health training programs that are used nationwide. Dr. North is interested in the various crises people have, and has also done a good deal of work with the homeless population. However, crisis psychiatry is just one focus out of many. Dr. North also studies the psychiatric effects of gastroenterological disease and dissociative disorders.

The Scope of Disaster

A great deal of Dr. North’s work over the years has been epidemiological. “It’s a complex field,” she says. “For example, there’s a theory that the most severe kinds of disasters are the intentional, man-made ones—terrorism. Maybe, if someone is aiming at you with malevolence and forethought, the psychological effects are more heinous than those resulting from even particularly devastating natural disasters. There’s some evidence supporting this, but it’s just a theory. To prove a theory of this sort, one would need to gather data from a wide variety of traumatic events.” Dr. North has been to the aftermath of 15 different traumatic events, and some interesting information has emerged; however, the number of variables that must be accounted for are staggering. Dr. North is currently conducting a federally funded study looking at the effects of 9/11 on people who were working in the World Trade Center and in the surrounding areas at the time. “With an act of terrorism of that scope and magnitude, it’s difficult to determine whether the severity of the psychological effects is due to the scope and magnitude, to the malevolence behind the act, or, if some mixture thereof, what proportion of the effect is due to which causal factor.”

Disorders Following Crises

In the majority of populations the most common psychiatric disorder following disasters is PTSD (not, however, delayed-onset PTSD as is sometimes seen with childhood abuse). The second most common diagnosis is major depression. However, Dr. North stresses that different populations have different issues. “We studied fire fighters who served as rescue and recovery workers after the Oklahoma City bombing, and their most common psychiatric disorder was alcohol abuse or dependence. However, virtually all of it was preexisting. In fact, we’ve found that, contrary to what some believe, new substance use disorders very seldom develop as a result of a traumatic experience.” The rates of PTSD in the fire fighters were much lower than the rates among people who were in the bomb blast. Perhaps this is to be expected, and, theoretically, professional emergency responders might, due to selection and self-selection for this work, training, the indirectness of their exposure, and experience with trauma, do better than civilians following a disaster. However, Dr. North suggests that the rates of PTSD in New York fire fighters who responded to 9/11 might be expected to be considerably higher; they were, in that crisis, also part of the victim group.

Dr. North and her team have seen a wide range in rates of psychiatric disorders following crises. They’ve seen PTSD rates ranging from ≤5% following the Oakland/Berkeley firestorm and a tornado in Florida, to ≥34% in victims of the Oklahoma City bombing and in hotel employees who were working in an Indianapolis Ramada Inn when a military jet crashed into the lobby. Dr. North says, “as many as 50% of disaster victims might develop PTSD or another psychiatric disorder, or as few as 10%. It depends on the disaster, the affected population, and a host of other mediating factors.”

It’s also important to distinguish between prevalence (all disorders) and incidence (only new disorders). Some disorders are very common in the general population, and most disorders following a disaster were preexisting. “We generally don’t see new cases of schizophrenia, bipolar disorder, or drug and alcohol use and dependence following a disaster,” Dr. North says.

Diagnosis

It’s important, when diagnosing a psychiatric disorder in a crisis survivor, to wait the proper amount of time. “Technically, you can’t diagnose major depression for at least two weeks, and you can’t diagnose PTSD for at least a month,” Dr. North says. “Often, people have early symptoms that quickly resolve, and failure to properly distinguish psychiatric illness from more general distress has hampered both clinical interventions and research.” Whether the symptoms persist and merit a diagnosis of psychiatric disorder or not, they usually begin very soon after the disaster, Dr. North says. “The majority of people who developed PTSD following the Oklahoma City bombing started presenting with symptoms the very day of the catastrophe.”

It comes down to clinical judgment, Dr. North explains. If a psychiatrist has a patient with PTSD symptoms 1 week after being exposed to a disaster, the psychiatrist can either treat the symptoms or, if he or she feels the patient is incubating PTSD, treat for PTSD. There is no easy answer, and the professional judgment of an experienced clinician is needed.

Conclusion

“Certain psychiatric disorders can be expected to occur with some frequency in the survivors of disasters,” Dr. North says. “Clinicians know how to treat these disorders, and we can provide interventions for others who’ve been severely traumatized. Questions for research are, what aspects of these crises are generating psychiatric disorders?, and what risk factors are attendant on different populations? The thing that continually amazes me, is how many victims of disasters don’t develop PTSD or depression. People are more resilient than we give them credit for.”

Disclosure: Dr. North reports no affiliation with or financial interest in any organization that may pose a conflict of interest.