Ten-Year Follow-Up of Earthquake Survivors: Long-Term Study on the Course of PTSD Following a Natural Disaster.

Objective: Few earthquake survivor studies extend follow-up beyond 2 years, leaving the long-term course of earthquake-related posttraumatic stress disorder (PTSD) unknown. This 10-year survey re-assessed the 1999 Izmit, Turkey, earthquake survivors.Methods: Izmit earthquake survivors (N = 198), previously assessed for PTSD/partial PTSD at 1-3 months and 18-20 months post-earthquake, were evaluated 10 years post-event from January 2009 through December 2010. A PTSD self-test (Turkish translation) used DSM-IV criteria to characterize full PTSD, "stringent partial PTSD," "lenient partial PTSD," or non-PTSD based on symptom type/amount.Results: Full PTSD prevalence decreased from 37% at 1-3 months post-earthquake to 15% at 18-20 months (P < .001), remaining relatively stable (12%) at 10 years (P = .38). Stringent and lenient partial PTSD decreased between 1-3 months and 18-20 months (from 9% to 3% and from 24% to 12%, respectively; P < .001), remaining stable at 10 years (5% and 9%, respectively; P = .43 and P = .89). PTSD was more prevalent at 1-3 months among those who had a close acquaintance harmed, had been evacuated for long periods (> 1 week), or had more children; this was not observed at 10 years (P = .007-.017). Avoidance symptoms 1-3 months post-earthquake were the best predictor for full PTSD at 10 years (P < .001). Delayed-onset PTSD was observed in only 2% of participants.Conclusions: Full and partial PTSD decreased over the first 2 years post-trauma, but remained stable at 10 years, suggesting PTSD symptoms at around 2 years remain stable at 10 years. Background characteristics did not predict PTSD long-term course, but avoidance level did. Delayed-onset PTSD was relatively rare.

Natural course of posttraumatic stress disorder: a 20-month prospective study of Turkish earthquake survivors.

OBJECTIVE: A 20-month prospective follow-up of survivors of the severe earthquake in Turkey in 1999 examined the natural course of posttraumatic stress disorder (PTSD) and the contribution of different symptom clusters to the emergence of PTSD. METHOD: Subjects were randomly sampled in a suburb of Istanbul that was severely affected by the earthquake. A total of 464 adults were assessed with a self-report instrument for PTSD symptoms on 3 consecutive surveys that were administered 1 to 3, 6 to 10, and 18 to 20 months following the earthquake. RESULTS: The prevalence of PTSD was 30.2% on the first survey and decreased to 26.9% and 10.6% on the second and third surveys, respectively. Female subjects showed initially higher (34.8%) PTSD rates compared with male subjects (19.1%). However, gender differences disappeared by the time of the third survey due to high spontaneous remission rates in female subjects. Low levels of chronic and delayed-onset PTSD were observed. A major contribution of the avoidance symptoms to PTSD diagnosis was identified by statistical analysis. CONCLUSIONS: Initial PTSD following an earthquake may be as prevalent as in other natural disasters, but high rates of spontaneous remission lead to low prevalence 1.5 years following the earthquake. Initial avoidance characteristics play a major role in the emergence of PTSD.