This study will test the effectiveness of writing about a traumatic incident to treat post-traumatic stress disorder in people who have been in car accidents.

Post-traumatic stress disorder (PTSD) is a chronic and debilitating disorder caused by experiencing a stressful or traumatic event. Although there is evidence that treatments for PTSD are effective, many people do not seek treatment or seek treatment only after their PTSD has become severe. This study will test a low-cost, brief, and easily implemented treatment that may encourage people to seek treatment for PTSD. The treatment, called written disclosure (WD), involves writing about the traumatic event that caused a person's PTSD. In this study, people who have PTSD as the result of a motor vehicle accident will test two versions of WD, one administered in a clinic and the other administered over the phone.

Participation in this study will last 5 weeks, with follow-up assessments continuing until 6 months after treatment. After screening, participants will be assigned to one of three conditions: WD treatment delivered in the clinic, WD treatment delivered via phone, and waitlist. The WD treatment involves five weekly writing sessions. During the first session, trauma reactions and the rationale for WD will be explained to all participants, and then participants will write for 30 minutes about their motor vehicle accident. The next four sessions will involve only writing for 30 minutes. For those receiving treatment in the clinic, a therapist will communicate directions and explanations to participants, and participants will have their heart rate activity recorded continuously for 5 minutes prior to writing and during the 30 minutes of writing. For those receiving treatment over the phone, explanations of the study will be provided in writing, and a study staff member will call participants before and after each writing session to ensure that participants understand the directions and are not experiencing any unexpected negative reactions after writing. Participants in the waitlist condition will not receive treatment for the first 4 months. After that period, they will be offered the WD treatment.

Assessments of all participants will occur at baseline, after treatment, and 3 months after treatment. Participants assigned to receive WD treatment, either in a clinic or via phone, will also be assessed 6 months after treatment. Assessments administered at these points will involve semi-structured clinical interviews, self-report questionnaires, and measures of mood-related symptoms. Participants receiving treatment will also complete self-report measurements of emotional response after each writing session and the Daily Experiences Questionnaire every day during the 5 weeks of treatment. Participants on the waitlist will also undergo assessments of suicidal thoughts and PTSD symptoms every 2 weeks.

Inclusion Criteria:

• Primary diagnosis of post-traumatic stress disorder
• Involved in motor vehicle accident that occurred at least 3 months ago

Exclusion Criteria:

• Current diagnosis of mania, hypomania, bipolar depression, psychotic disorder, substance abuse disorder, or severe depression
• History of psychosis
• Active suicidality or history of two or more suicide gestures or attempts in the past year
• Significant cognitive impairment
• Current participation in a psychosocial treatment, such as individual or group therapy led by a clinician