Background. Brief interventions are needed in dealing with traumatic stress problems in large survivor populations after devastating earthquakes. The present study examined the effectiveness of a single session of exposure to simulated tremors in an earthquake simulator and self-exposure instructions in reducing post-traumatic stress disorder (PTSD).

Method. Participants were consecutively recruited from among survivors screened during field surveys in the disaster region in Turkey. Thirty-one earthquake survivors with PTSD were assigned either to a single session of behavioural treatment (n=16) or to repeated assessments (RA; n=15). Assessments in the treatment group were at 4, 8, 12, 24 weeks and 1–2 years post-treatment. The RA cases were assessed at baseline and 4 and 8 weeks after trial entry, after which they received the same treatment and were followed up at 4, 12, 24 weeks and 1–2 years.

Results. Between-group treatment effects at week 8 were significant on measures of fear, PTSD and self- and assessor-rated global improvement. Improvement rates were 40% at week 4, 72% at week 12, 80% at week 24, and 80% at 1–2-years' follow-up, with large effect sizes on fear and PTSD measures. Post-session reduction in fear of earthquakes and increased sense of control over fear at follow-up related to improvement in PTSD.

Conclusion. The study provided further evidence of the effectiveness of a single session of behavioural treatment in reducing fear and PTSD in earthquake survivors. Future research needs to examine the usefulness of earthquake simulators in increasing psychological preparedness for earthquakes.