Recovery from DSM-IV post-traumatic stress disorder in the WHO World Mental Health surveys

Background: Research on post-traumatic stress disorder (PTSD) course finds a substantial proportion of cases remit within six months, a majority within two years, and a substantial minority persists for many years. Results are inconsistent about pre-trauma predictors.
Methods: The WHO World Mental Health surveys assessed lifetime DSM-IV PTSD presence-course after one randomly-selected trauma, allowing retrospective estimates of PTSD duration. Prior traumas, childhood adversities (CAs), and other lifetime DSM-IV mental disorders were examined as predictors using discrete-time person-month survival analysis among the 1,575 respondents with lifetime PTSD.
Results: 20%, 27%, and 50% of cases recovered within three, six, and 24 months and 77% within 10 years (the longest duration allowing stable estimates). Time-related recall bias was found largely for recoveries after 24 months. Recovery was weakly related to most trauma types other than very low (OR=0.2-0.3) early-recovery (within 24 months) associated with purposefully injuring/torturing/killing and witnessing atrocities and very low later-recovery (25+ months) associated with being kidnapped. The significant odds-ratios for prior traumas, CAs, and mental disorders were generally inconsistent between early- and later-recovery models. Cross-validated versions of final models nonetheless discriminated significantly between the 50% of respondents with highest and lowest predicted probabilities of both early-recovery (66-55% versus 43%) and later-recovery (75-68% versus 39%).
Conclusions: We found PTSD recovery trajectories similar to those in previous studies. The weak associations of pre-trauma factors with recovery, also consistent with previous studies, presumably are due to stronger influences of post-trauma factors.