Suicide

Psychological Trauma and PTSD

It is well known that not all traumatic events result in clinical manifestation of PTSD. Even those who experience a horrifying event do not necessarily develop PTSD. In a general population, traumatic exposure is quite common, ranging from 40% to 90% depending on population and assessments. Among those who have had a qualifying traumatic event, 15% to 25% develop PTSD. Types of traumatic events most likely to result in PTSD are brief but overwhelming, such as an assault, an accident, and a catastrophic disaster. Rape, kidnapping, and torture for women, and rape and combat for men, are known to have the highest probability (ranging from 39% to 65%) of resulting in a clinical PTSD. However, the evidence suggests that chronic traumatization such as childhood abuse and a violent domestic relationship also likely result in PTSD.

PTSD and Suicidality

The association of early or devastating traumatization, such as childhood abuse and war trauma, with suicidality has been long suspected. However, the evidence of PTSD's involvement as a mediating factor has not been clearly demonstrated until recently. Most studies documenting the association between PTSD and suicidality have been observational studies. Nonetheless, an independent effect of PTSD on suicidality controlling for confounding factors is supported in a few general population studies.

It has been more tenuous to demonstrate an independent effect of PTSD on completed suicide. Using a Danish population registry-based nested case-control sample, Jaimie Gradus and associates demonstrated a strong association of PTSD and completed suicide. In this study, the odds ratio was 5.3 with the confidence interval of 3.4 to 8.1 after controlling for other psychiatric disorders and demographic measures. This means that those people with PTSD were five times more likely to commit suicide when other factors are simultaneously considered. Because psychiatric disorder identification was based on medical records, those with PTSD in this study might have represented a severe spectrum of the disorder. Prospective studies, however, have produced mixed results on this association. A recent systematic meta-analysis study concluded that the direct effect of PTSD is limited to nonfatal suicidality. This conclusion should be taken with a caution. As is usually the case with most prospective studies of suicide, a lack of power and paucity of such studies are hurdles for arriving at conclusive evidence. Furthermore, the complexity of the pathways leaves the possibility for several other indirect effects on suicide. For example, chronic PTSD may transform into a form of depression over time as avoidance/numbing symptoms overtake other hallmark PTSD symptoms such as memory recollection and hyperarousal. Then the diagnosis of major depression that overwrites PTSD is an antecedent to complete suicide.

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