Defining the index trauma in post-traumatic stress disorder patients with multiple trauma exposure: impact on severity scores and treatment effects of using worst single incident versus multiple traumatic events

Abstract

Background: A diagnosis of post-traumatic stress disorder (PTSD) requires the identification of one or more traumatic events, designated the index trauma, which serves as the basis for assessment of severity of PTSD. In patients who have experienced more than one traumatic event, severity may depend on the exact definition of the index trauma. Defining the index trauma as the worst single incident may result in PTSD severity scores that differ from what would be seen if the index trauma included multiple events.Objective: This study aimed to investigate the impact of the definition of the index trauma on PTSD baseline severity scores and treatment outcome.Method: A planned secondary analysis was performed on data from a subset (N = 58) of patients enrolled in a trial evaluating the efficacy of a 12 week residential dialectical behavioural therapy programme for PTSD related to childhood abuse (DBT-PTSD). Assessments of the severity of PTSD were conducted at admission, at the end of the 12 week treatment period, and at 6 and 12 weeks post-treatment, using the Clinician-Administered PTSD Scale. The index trauma was defined with respect to both the worst single incident and up to three qualitatively distinct traumatic events.Results: When the index trauma included multiple traumas, PTSD severity scores were significantly higher and improvements from pre- to post-treatment were significantly lower than when the index trauma was defined as the worst single incident.Conclusions: In patients with PTSD who have experienced multiple traumas, defining the index trauma as the worst single incident may miss some aspects of clinically relevant symptomatology, thereby leading to a possibly biased interpretation of treatment effects. In DBT-PTSD, treatment effects were lower when the index trauma included multiple traumatic events. More research is needed to determine the impact of the various index trauma definitions on the evaluation of other trauma-focused treatments.

Occupational Risk for Post-Traumatic Stress Disorder and Trauma-Related Depression: A Systematic Review with Meta-Analysis

“…PTSD might not only develop as a consequence of a single traumatic event, but it might also result after exposure to multiple events over time. As Priebe et al, 2018 [ 60 ] suggest, there may be repeated micro-aggressions against police officers or psychiatric staff, and paramedics and emergency doctors might be exposed to multiple experiences of serious accidents, possibly lacking a single worst incident. Accordingly, the DSM-IV (American Psychiatric Association 2000 [ 61 ]) Criterion A “has been exposed to a traumatic event” has been modified in the DSM-5 (American Psychiatric Association 2013 [ 62 ]) to “traumatic event(s),” therefore comprising multiple events or a recurring exposure.…”

World Trade Center exposure, post‐traumatic stress disorder, and subjective cognitive concerns in a cohort of rescue/recovery workers

“…These data raise the possibility that PTSD symptoms in FDNY WTC rescue/recovery workers result from experiencing multiple traumatic exposures. This type of PTSD has been associated with increased symptom severity and worse outcomes when compared with single‐incident PTSD .…”

Associations Among Childhood Trauma, Childhood Mental Disorders, and Past‐Year Posttraumatic Stress Disorder in Military and Civilian Men

“…However, the risk of PTSD in persons with childhood vulnerabilities relates to all childhood common mental disorders, such as anxiety and depression, rather than childhood anxiety or PTSD alone. In addition, the relatively high rates of high childhood trauma counts and multiple adult trauma exposures in the ADF has implications for PTSD symptom severity and treatability in military populations (Priebe et al., ). However, this understanding should not negate the role of combat traumas and other trauma exposures in military service as risk factors of disorder but rather be used to better inform and manage the level of risk.…”

“…Over time, the literature has increasingly focused on PTSD as a product of traumatic experiences over the lifespan rather than as the product of a single traumatic incident, as defined in the diagnostic criteria (Priebe et al., ). In keeping with this research, civilian and military studies have demonstrated an association between childhood adversity and adult PTSD (Bremner, Southwick, Johnson, Yehuda, & Charney, ; Brewin, Andrews, & Valentine, ; Cabrera, Hoge, Bliese, Castro, & Messer, ; Iversen et al., ; Ozer, Best, Lipsey, & Weiss, ).…”