Subthreshold posttraumatic stress disorder in the world health organization world mental health surveys

Abstract

Background Although only a minority of people exposed to a traumatic event (TE) develops PTSD, symptoms not meeting full PTSD criteria are common and often clinically significant. Individuals with these symptoms have sometimes been characterized as having sub-threshold PTSD, but no consensus exists on the optimal definition of this term. Data from a large cross-national epidemiological survey are used to provide a principled basis for such a definition.

Methods The WHO World Mental Health (WMH) Surveys administered fully-structured psychiatric diagnostic interviews to community samples in 13 countries containing assessments of PTSD associated with randomly selected TEs. Focusing on the 23,936 respondents reporting lifetime TE exposure, associations of approximated DSM-5 PTSD symptom profiles with six outcomes (distress-impairment, suicidality, comorbid fear-distress disorders, PTSD symptom duration) were examined to investigate implications of different sub-threshold definitions.

Results Although consistently highest distress-impairment, suicidality, comorbidity, and symptom duration were observed among the 3.0% of respondents with DSM-5 PTSD than other symptom profiles, the additional 3.6% of respondents meeting two or three of DSM-5 Criteria BE also had significantly elevated scores for most outcomes. The proportion of cases with threshold versus sub-threshold PTSD varied depending on TE type, with threshold PTSD more common following interpersonal violence and sub-threshold PTSD more common following events happening to loved ones.

Conclusions Sub-threshold DSM-5 PTSD is most usefully defined as meeting two or three of the DSM-5 Criteria B-E. Use of a consistent definition is critical to advance understanding of the prevalence, predictors, and clinical significance of sub-threshold PTSD.