Mental Health Consequences of Traumatic Brain Injury

Abstract

Traumatic brain injury (TBI) is associated with a host of psychiatric and neurobehavioral problems. As mortality rates have declined for severe TBI, attention has turned to the cognitive, affective, and behavioral sequelae of injuries across the severity spectrum, which are often more disabling than residual physical effects. Moderate and severe TBI can cause personality changes including impulsivity, severe irritability, affective instability, and apathy. Mild TBI, once considered a largely benign phenomenon, is now known to be associated with a range of affective symptoms, with suicidality, and with worsening or new onset of several psychiatric disorders including posttraumatic stress disorder and major depressive disorder. Repetitive head impacts, often in athletic contexts, are now believed to be associated with a number of emotional and behavioral sequelae. The nature and etiology of mental health manifestations of TBI (including a combination of brain dysfunction and psychological trauma and interrelationships between cognitive, affective, and physical symptoms) are complex and have been a focus of recent epidemiological and mechanistic studies. This paper will review the epidemiology of psychiatric and neurobehavioral problems after TBI in military, civilian, and athletic contexts.

Keywords: Cognition; Generalized anxiety disorder; Major depressive disorder; Posttraumatic stress disorder; Suicidality; Traumatic brain injury.

Figure 1:

Annual prevalence of different classes of psychiatric disorder in the prospective study of moderate-severe TBI from Alway et al. (54). Diagnostic and Statistical Manual of Mental Disorders—Fourth Edition (DSM-IV) Axis I diagnoses were determined via structured clinical interview. Mood, anxiety, and substance use disorders were most prevalent DSM-IV Axis I disorders across five years of follow-up post-injury, with a steady decline in prevalence over time.

Figure 2:

Percentage of individuals with moderate-severe TBI from Alway et al. (54) who met criteria for each psychiatric disorder class in each year of follow-up post-injury, stratified by whether it was the first time being diagnosed post-injury (solid color) or recurring from prior post-injury study visits, and whether or not participants had a pre-injury history of a disorder in that diagnostic class (grey = pre-injury history; orange = no pre-injury history). The first year post-injury was the primary period of vulnerability for the appearance of psychiatric disorders post-TBI (solid colors). Although having a pre-injury psychiatric disorder (grey) was a strong predictor of having disorders post-injury, mood and anxiety disorders in particular often presented in individuals with no pre-injury history (orange) of these types of disorders.