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

BACKGROUND

Although only a few people exposed to a traumatic event (TE) develop posttraumatic stress disorder (PTSD), symptoms that do not meet full PTSD criteria are common and often clinically significant. Individuals with these symptoms sometimes have been characterized as having subthreshold PTSD, but no consensus exists on the optimal definition of this term. Data from a large cross-national epidemiologic survey are used in this study to provide a principled basis for such a definition.

METHODS

The World Health Organization World Mental Health 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 subthreshold definitions.

RESULTS

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

CONCLUSIONS

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

Attention to threat images in individuals with clinical and subthreshold symptoms of post-traumatic stress disorder

Attention to general and trauma-relevant threat was examined in individuals with clinical and subthreshold symptoms of post-traumatic stress disorder (PTSD). Participants' eye gaze was tracked and recorded while they viewed sets of four images over a 6-s presentation (one negative, positive, and neutral image, and either a general threat image or a trauma-relevant threat image). Two trauma-exposed groups (a clinical and a subthreshold PTSD symptom group) were compared to a non-trauma-exposed group. Both the clinical and subthreshold PTSD symptom groups attended to trauma-relevant threat images more than the no-trauma-exposure group, whereas there were no group differences for general threat images. A time course analysis of attention to trauma-relevant threat images revealed different attentional profiles for the trauma-exposed groups. Participants with clinical PTSD symptoms exhibited immediate heightened attention to the images relative to participants with no-trauma-exposure, whereas participants with subthreshold PTSD symptoms did not. In addition, participants with subthreshold PTSD symptoms attended to trauma-relevant threat images throughout the 6-s presentation, whereas participants with clinical symptoms of PTSD exhibited evidence of avoidance. The theoretical and clinical implications of these distinct attentional profiles are discussed.

Risk for PTSD symptom worsening during new PTSD treatment episode in a nationally representative sample of treatment-seeking U.S. veterans with subthreshold PTSD

Previous research has examined risk factors associated with poorer treatment outcomes for military Veterans with PTSD. However, work has not examined risk for symptom worsening among Veterans with subthreshold PTSD. The aim of this study was to examine demographic, psychiatric, physical health, and pre-treatment PTSD symptom clusters associated with clinically significant worsening of PTSD among a nationally representative sample of United States (U.S.) Veterans with subthreshold PTSD. Participants were Veterans (weighted N = 3162; unweighted N = 236) with subthreshold PTSD entering a new episode of treatment at U.S. Veterans Affairs PTSD specialty clinics during fiscal years 2018 and 2019. Data was collected as part of the Veterans Outcome Assessment, a yearly baseline and 3-month follow-up telephone survey. Analyses used weighted calculations to support the use of VOA data to draw inferences about all eligible Veterans, and binary logistic regression was used to examine risk factors for symptom worsening. Over 1/3 (37.7%) of Veterans with subthreshold PTSD experienced clinically significant symptom worsening from baseline to follow-up. Adjusted analyses revealed several risk factors for symptom worsening, including demographic (e.g., male sex, White race), psychiatric (personality and anxiety disorders), health care utilization (e.g., more primary care encounters in the previous year), physical health disability, and specific baseline PTSD symptom clusters (negative affect and anxious arousal). Findings suggest that Veterans with subthreshold symptoms seeking treatment for PTSD are at risk for symptom worsening, and highlight the importance of assessment, prevention, and treatment in targeting veterans with PTSD symptoms below the diagnostic threshold.

Clinical relevance of subthreshold PTSD versus full criteria PTSD following traumatic brain injury in U.S. service members and veterans

BACKGROUND

The purpose of this cross-sectional study was to examine the influence of subthreshold posttraumatic stress disorder (PTSD) and full PTSD on quality of life following mild traumatic brain injury (mTBI).

METHODS

Participants were 734 service members and veterans (SMV) classified into two injury groups: uncomplicated mild TBI (MTBI; n = 596) and injured controls (IC, n = 139). Participants completed a battery of neurobehavioral measures, 12-or-more months post-injury, that included the PTSD Checklist Civilian version, Neurobehavioral Symptom Inventory, and select scales from the TBI-QOL and MPAI. The MTBI group was divided into three PTSD subgroups: No-PTSD (n = 266), Subthreshold PTSD (n = 139), and Full-PTSD (n = 190).

RESULTS

There was a linear relationship between PTSD severity and neurobehavioral functioning/quality of life in the MTBI sample. As PTSD severity increased, significantly worse scores were found on 11 of the 12 measures (i.e.

, MTBI

Full-PTSD > Sub-PTSD > No-PTSD). When considering the number of clinically elevated scores, a linear relationship between PTSD severity and neurobehavioral functioning/quality of life was again observed in the MTBI sample (e.g., 3-or-more elevated scores: Full-PTSD = 92.1 %, Sub-PTSD = 61.9 %, No-PTSD = 19.9 %).

LIMITATIONS

Limitations included the use of a self-report measure to determine diagnostic status that may under/overcount or mischaracterize individuals.

CONCLUSION

PTSD symptoms, whether at the level of diagnosable PTSD, or falling short of that because of the intensity or characterization of symptoms, have a significant negative impact on one's quality of life following MTBI. Clinicians' treatment targets should focus on the symptoms that are most troubling for an individual and the individual's perception of quality of life, regardless of the diagnosis itself.