Anxiety disorders encompass psychiatric conditions that include generalized anxiety disorder (GAD), obsessive–compulsive disorder, panic disorder, acute stress disorder (ASD), PTSD, and social phobias (National Institute of Mental Health, 2008). According to Kessler et al. (2005), about 40 million Americans 18 years old and older suffer from anxiety disorders, which are often comorbid with alcohol or drug abuse. Several types of anxiety disorders— including PTSD, GAD, and panic disorder—that could be associated with service in the Gulf War have been studied in relation to TBI. They are described briefly below.
PTSD is a psychiatric disorder that can develop after the direct, personal experience of or witnessing of an often life-threatening event. Symptoms that characterize PTSD include re-experiencing of an extremely traumatic event through flashbacks and nightmares, avoidance of things associated with the trauma, and hyperarousal (difficulty in sleeping and in concentrating) (IOM, 2006).
GAD is characterized by chronic anxiety and exaggerated worry. Often, the worries are accompanied by physical symptoms, such as fatigue, headaches, and irritability. Like GAD, panic disorder is accompanied by physical symptoms that may include chest pain, heart palpitations, shortness of breath, dizziness, or abdominal distress due to unexpected and repeated episodes of acute intense fear.
Bryant and Harvey (1999a) conducted a prospective cohort study to compare rates of ASD and PTSD in motor-vehicle-accident survivors who sustained a mild TBI with rates in survivors without a TBI. Patients were consecutively identified at a major trauma center in New South Wales, Australia, over a 10-month period. Mild TBI was defined on the basis of PTA of less than 24 hours. The study included 79 mild-TBI patients (55 males and 24 females) and 92 patients without TBI (61 males and 31 females) who were evaluated for ASD 2–25 days after trauma. A psychiatric assessment at 6 months after injury included an assessment of ASD through the Acute Stress Disorder Interview and of PTSD through the PTSD module of the Composite International Diagnostic Interview (CIDI). Interviews were completed for 63 (80%) mild-TBI patients and 71 (77%) of the controls. Injury severity score (ISS) was greater in mild-TBI (9.28) than in controls (4.0; p < 0.001). During the acute and 6-month followup evaluations, controls reported fear and helplessness more often than patients with mild TBI. They were also more likely to report intrusive memories during the acute phase. There was no significant difference between mild-TBI patients and controls in the rates of ASD—11 patients (14%) and12 patients (13%), respectively—or the rate of PTSD—15 patients (24%) and 18 patients (25%), respectively.
In a separate analysis of the same mild-TBI population, Bryant and Harvey (1999b) evaluated the relationship between PTSD and postconcussive symptoms (PCSs). The analysis included 105 survivors of motor-vehicle accidents who either sustained a mild TBI or did not. At the 6-month followup, 46 mild-TBI patients (32 male and 14 female; mean ISS, 8.96; standard deviation [SD], 6.08) and 59 controls (31 male and 28 female; mean ISS, 3.92; SD, 3.74) were evaluated. Assessments administered at 6 months were the PTSD module from the CIDI and the