Scientists Find Direct Link Between Amount of Loss Suffered During an Earthquake and The Likelihood of PTSD

Researchers at the Johns Hopkins School of Public Health have found that the intensity and degree of loss experienced by survivors during an earthquake are directly related to the chance that a survivor will go on to suffer from post-traumatic stress syndrome disorder (PTSD). The authors also found that having a higher level of education and going through the earthquake with another human being protected survivors from PTSD. Thought to be the first large-scale population-based investigation of the psychological effects of a major earthquake, the study appears in the July issue of Acta Psychiatrica Scandinavica.

The researchers attempted to link psychological distress following the 1988 earthquake in northern Armenia to independent assessments of trauma exposure to human and material losses experienced by survivors. Lead author Haroutune K. Armenian, MD, DrPH, MPH, professor, Epidemiology, Johns Hopkins School of Public Health, says, "About half of the adult participants in this study were identified as fulfilling the criteria for PTSD in the two years following the disaster. Such a frequency in occurrence of a serious condition highlights the need to address this disorder as a major public health priority."

Soon after the 1988 earthquake, the scientists interviewed 34,743 survivors to assess three categories of material loss: cumulative family loss (including losses of furniture, cars, appliances, and money); the maximum damage to the residence; and the estimated total losses in rubles. Next, starting in 1990, the scientists randomly selected from this large initial group 1,785 survivors to determine any who had specific psychologic problems relevant to disasters.

Over 49 percent of these 1785 interviewees satisfied the criteria for PTSD listed in the Diagnostic and Statistical Manual of Mental Disorders, Third Edition (DSM-III-R), but only 154 satisfied criteria for PTSD alone without other psychopathology. To prevent errors of diagnostic misclassification, the researchers included in the study only these 154 "pure" cases of PTSD, and compared them with 583 controls who had no symptoms indicative of the psychiatric diagnoses of interest.

People from Spitak, the town located nearest the quake's epicenter, were almost eight times more likely to develop PTSD than were the controls, and survivors from nearby Gumri (the largest city with most damage) were over six times more likely. One's risk of PTSD increased directly with the total amount of loss sustained, so that people who suffered the highest levels of loss were 4.1 times more likely than controls to have PTSD. A family's total loss estimate in rubles most comprehensively reflected the relationship between a person's loss and his or her risk for PTSD, with those losing 20,000 rubles or more being over eight times more likely than controls to suffer from PTSD during the first year after the quake.

The type of building survivors were in at the time of the quake, or how they acted during it, did not affect who ended up with PTSD. The more education a person had, on the other hand, the lower was his or her risk of the disorder. Similarly, persons who lived through the earthquake with the support of another human being were 40 percent less likely to acquire the condition. Interestingly, the people without PTSD reported making new friends after the earthquake, something the people with PTSD didn't report.

Dr. Armenian said, "These findings help us identify a subgroup of earthquake survivors, those victims with the lowest educational level and the greatest level of losses, who are at high risk for PTSD after the disaster. Targeting these two groups for immediate material replacement and early social support may have important preventive implications."

The 1988 earthquake in northern Armenia killed 25,000 and left 700,000 homeless.

Support for this study was provided by a grant from the Armenian Relief Society, Inc., Watertown, MA 02172.