Traumatic events are a common part of the human experience. Posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) are common sequelae of trauma that are both associated with poor physical health and mortality. The objective of this dissertation is to identify common and unique risk factors for each disorder in order to identify at-risk groups for PTSD and/or depression following trauma.
his dissertation is organized into five parts: 1) an introduction, 2) a simulation study exploring the use of test equating methods to standardize the Hospital Anxiety and Depression Scale (HADS) to the Beck Depression Inventory II (BDI) in order to create common depression scale across studies in a pooled analysis, 3) an individual participant data meta-analysis on risk factors for PTSD and depression following incident trauma, 4) a Mendelian Randomization analysis of childhood abuse victimization and neuroticism on PTSD and depression, 5) a discussion of the findings and avenues for future research.
The simulation study found that an Equated BDI diagnosis had higher specificity (range: 0.86 to 0.91) compared to using the HADS diagnosis (range: 0.80 to 0.82) when the correlation between the BDI and HADS was greater than 0.7, but had lower sensitivity (Equated BDI range: 0.67 to 0.72; HADS range: 0.84 to 0.92). The Equated BDI diagnosis was found to improve statistical power when the prevalence of depression was 20% or higher with greater improvements when the proportion of studies assessing the depression with the HADS was less than 50%.
In the individual participant data meta-analysis, common risk factors for acute and persistent MDD and PTSD were found including increased risk for female sex and reduced risk for those who experienced an accident versus an assault or other traumatic event as the index trauma. Acute MDD symptom severity was associated with persistent PTSD and remained significant after inclusion of acute PTSD symptom severity. In an analysis of PTSD symptom clusters, only reexperiencing symptoms were associated with persistent PTSD along with MDD symptom severity. In models of persistent MDD, acute PTSD symptom severity was associated with persistence, but neither overall symptom severity nor cluster symptom severities were associated with persistence after inclusion of acute MDD symptom severity. In the Mendelian Randomization analysis, childhood abuse victimization was found to be associated with PTSD symptom severity but was not associated with an increased odds of a MDD diagnosis, while neuroticism was associated with an increased odds of a diagnosis of MDD, but was not associated with an increase in PTSD symptom severity.
Findings from the meta-analysis that leveraged the use of item-response theory imply that while PTSD and MDD share many risk factors for onset of symptoms following the experience of a traumatic event, persistence of symptoms depends most strongly on initial symptoms. However, PTSD and MDD were also found to have different relationships with childhood abuse victimization and neuroticism, indicating that some risk factors are unique to each disorder. Future studies can build upon these results, especially when pooling data from different studies, to further explicate the associations between PTSD, MDD, and their causes.
| Identifer | oai:union.ndltd.org:columbia.edu/oai:academiccommons.columbia.edu:10.7916/tmn0-sa53 |
| Date | January 2023 |
| Creators | Koenen, Karestan C. |
| Source Sets | Columbia University |
| Language | English |
| Detected Language | English |
| Type | Theses |
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