The course of PTSD in naturalistic long-term studies: high variability of outcomes. A systematic review

With a lifetime prevalence of 8% posttraumatic stress disorder (PTSD) is one of the most common mental disorders; nevertheless, its longitudinal course is largely unknown.

Our aim was to conduct a systematic review summarizing available findings on the prospective, naturalistic long-term course of PTSD and its predictors.

Databases MEDLINE and PsycINFO were searched. Main selection criteria were: 1) naturalistic cohort study with a follow-up period of at least 3 years, 2) adult participants with observer-rated or probable PTSD at baseline.

Twenty-four cohorts (25 studies) were retrieved (14 with observer-assessed, 10 with probable PTSD). In total, they comprised about 10,500 participants with PTSD at baseline that were included in the long-term follow-ups. Studies investigating patient populations with observer-assessed PTSD found that between 18% and 50% of patients experienced a stable recovery within 3-7 years; the remaining subjects either facing a recurrent or a more chronic course. Outcomes of community studies and studies investigating probable PTSD varied considerably (remission rates 6-92%). Social factors (e.g. support) as well as comorbid physical or mental health problems seem to be salient predictors of PTSD long-term course and special focus should be laid on these factors in clinical settings.

Included studies differed notably with regard to applied methodologies. The resulting large variability of findings is discussed. More standardized systematic follow-up research and more uniformed criteria for remission and chronicity are needed to gain a better insight into the long-term course of PTSD.