Post-traumatic Stress Disorder After Traumatic Brain Injury—A Systematic Review and Meta-Analysis

DOI: https://doi.org/10.1007/s10072- 020- 04458- 7

Abstract-Summary To estimate the relative frequency and relative risk of post-traumatic stress disorder (PTSD) attributed to traumatic brain injury (TBI).

In civilian populations, relative frequency of PTSD following TBI was 12.2% after 3 months (CI-95 (7.6–16.8%) I2  =  83.1%), 16.3% after 6 months (CI-95 (10.2–22.4%), I2 = 88.4%), 18.6% after 12 months (CI-95 (10.2–26.9%), I2 = 91.5%), and 11.0% after 24 months (CI-95 (0.0–25.8%), I2 = 92.0%).

Relative risk was 1.67 after 3 months (CI-95 (1.17–2.38), P = 0.011, I2 = 49%), 1.36 after 6 months (CI-95 (0.81–2.30), P  =  0.189, I2  =  34%), and 1.70 after 12 months (CI-95 (1.16–2.50), P = 0.014, I2 = 89%).

In military populations, the relative frequency of associated PTSD was 48.2% (CI-95 (44.3–52.1%), I2 = 100%) with a relative risk of 2.33 (CI-95 (2.00–2.72), P < 0.0001, I2 = 99.9%).

TBI is a risk factor for PTSD in clinic-based civilian populations. There are insufficient data to assess the relative frequency or relative risk of

PTSD in moderate to severe TBI.

Extended: In civilian populations, none of the study-level characteristics were

associated with the relative frequency of PTSD attributed to TBI.

In military populations, lower relative frequencies were observed for the follow- ing study-level characteristics: survey-based samples, status as active-duty service- members, and TBI subjects assessed within 12 months of return from deployment. Funnel plots were not asymmetric at visual inspection and Egger’s test did not

reveal any statistically significant asymmetry.

Introduction Patients with PTSD attributed to TBI often display symptoms such as headaches [49], anxiety [50], and depression [51], all of which are among the leading causes of disability worldwide [52].

Inconsistent findings on the prevalence of PTSD attributed to TBI means that it is difficult to assess the actual scope of the public health burden imposed by TBI- associated PTSD.

We therefore decided to perform a systematic review and meta-analysis of PTSD

attributed to TBI in civilian and military populations.

Meta-analysis was performed to estimate pooled relative frequencies and relative

risk of PTSD attributed to TBI.

Methods We calculated effect sizes for each study population regardless of TBI severity and, when possible, for studies where subjects could be classified by our definition as “mild TBI only” or “moderate to severe TBI.”

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Post-concussion Syndrome

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Most civilian studies reported the intervals between the TBI and the PTSD

assessment.

We therefore grouped the results from each study into the following groups based on the time between TBI and PTSD assessment: [1:3] = 3 months, [3:6] = 6 months, [6:12] = 12 months, [12:24] = 24 months.

The following confounding variables were evaluated: sample source: clinic- based, community- or population-based, and registry- or data-based; military ser- vice status; deployment status; TBI assessment method; TBI severity mild only; type of comparison group; DSM version; PTSD instrument type; PTSD as primary outcome and study quality >75% vs. ≤75%. Results Meta-regression was performed for studies reporting the relative frequency of TBI of any severity at 3, 6, and 12 months in non-population-based studies.

Meta-regression was performed separately for relative frequency and relative

risk of TBI-associated PTSD, for TBI of any severity, and mild TBI only.

For deployment status, relative frequency was significantly higher in studies that assessed subjects more than 12 months after return from deployment, including samples with subjects where the time of return from deployment was not reported, in samples with deployed and non-deployed subjects, and in samples where deploy- ment status was unknown (reference variable: within 12 months).

Only sampling source was associated with relative risk, with relative risk being

higher in survey-based studies with TBI of any severity.

Funnel plots for studies reporting relative frequency and relative risk of TBI- associated PTSD in TBI of any severity and mild TBI only, are presented in the supplementary material.

Discussion After pooling results from 31 civilian studies and 104 military studies, we have demonstrated that 11.0–18.6% of civilians develop PTSD within a 2-year period following a TBI, while 48.2% of servicemembers or veterans have TBI- associated PTSD.

The rates of PTSD following a military-related TBI are higher than those seen

following civilian-related TBI.

In civilian populations, none of the study-level characteristics were associated

with the relative frequency of PTSD attributed to TBI.

In military populations, lower relative frequencies were observed for the fol- lowing study-level characteristics: survey-based samples, status as active-duty servicemembers, and TBI subjects assessed within 12 months of return from deployment.

These military studies could have a selection bias towards TBI subjects, who are

more likely to present with PTSD.

One recent meta-analysis of PTSD following TBI, concluded that injury severity

did not affect the relative frequency and relative risk of PTSD [53].

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5 Future Directions

Conclusions and Future Directions In order to standardize assessments of PTSD and TBI in research settings, epide- miological studies with rigorous methodology and an international consensus are needed.

Study-level characteristics (i.e., TBI severity, LOC, GCS, PTA, pre-trauma psy- chiatric history) should be systematically recorded to enable analysis of PTSD pre- dictors in TBI patients, including the impact of TBI severity.

TBI-related PTSD constitutes a large-scale public health burden and a concerted effort is much warranted to address the devastating impact on patients and their families.

Considerable heterogeneity in the relative frequency of TBI-related PTSD under- scores the need for an international standardization of epidemiological studies, so to better elucidate the enormous burden and societal costs for both civilian and mili- tary populations.

Acknowledgement A machine generated summary based on the work of Iljazi, Afrim; Ashina, Håkan; Al-Khazali, Haidar Muhsen; Lipton, Richard B.; Ashina, Messoud; Schytz, Henrik W.; Ashina, Sait 2020 in Neurological Sciences.

Post-traumatic Headache in Children and Adolescents