PTSD has a unique position as the only psychiatric diagnosis (along with acute stress disorder ) that depends on a factor outside the individual, namely, a traumatic stressor. A patient cannot be given a diagnosis of PTSD unless he or she has been exposed to an event that is considered traumatic. These events include such obvious traumas as rape, military combat, torture, genocide, natural disasters, and transportation or workplace disasters. In addition, it is now recognized that repeated traumas or such traumas of long duration as child abuse , domestic violence, stalking, cult membership, and hostage situations may also produce the symptoms of PTSD in survivors.
A person suffering from PTSD experiences flashbacks, nightmares, or daydreams in which the traumatic event is experienced again. The person may also experience abnormally intense startle responses (hypervigilance) , insomnia , and may have difficulty concentrating. Trauma survivors with PTSD have been effectively treated with group therapy or individual psychological therapy, and other therapies have helped individuals, as well. Some affected individuals have found support groups or peer counseling groups helpful. Treatment may require several years, and in some cases, PTSD may affect a person for the rest of his or her life.
When PTSD was first suggested as a diagnostic category for DSM-III in 1980, it was controversial precisely because of the central role of outside stressors as causes of the disorder. Psychiatry has generally emphasised the internal weaknesses or deficiencies of individuals as the source of mental disorders; prior to the 1970s, war veterans, rape victims, and other trauma survivors were often blamed for their symptoms and regarded as cowards, moral weaklings, or masochists. The high rate of psychiatric casualties among Vietnam veterans, however, led to studies conducted by the Veterans Administration. These studies helped to establish PTSD as a legitimate diagnostic entity with a complex set of causes.
BIOCHEMICAL/PHYSIOLOGICAL CAUSES. Present neurobiological research indicates that traumatic events cause lasting changes in the human nervous system, including abnormal secretions of stress hormones. In addition, in PTSD patients, researchers have found changes in the amygdala and the hippocampus—the parts of the brain that form links between fear and memory. Experiments with ketamine, a drug that inactivates one of the neurotransmitter chemicals in the central nervous system, suggest that trauma works in a similar way to damage associative pathways in the brain. Positron emission tomography (PET) scans of PTSD patients suggest that trauma affects the parts of the brain that govern speech and language.
SOCIOCULTURAL CAUSES. Studies of specific populations of PTSD patients (combat veterans, survivors of rape or genocide, former political hostages or prisoners, etc.) have shed light on the social and cultural causes of PTSD. In general, societies that are highly authoritarian, glorify violence, or sexualize violence have high rates of PTSD even among civilians.
OCCUPATIONAL FACTORS. Persons whose work exposes them to traumatic events or who treat trauma survivors may develop secondary PTSD (also known as compassion fatigue or burnout). These occupations include specialists in emergency medicine, police officers, firefighters, search-and-rescue personnel, psychotherapists, disaster investigators, etc. The degree of risk for PTSD is related to three factors: the amount and intensity of exposure to the suffering of trauma victims; the worker’s degree of empathy and sensitivity; and unresolved issues from the worker’s personal history.
PERSONAL VARIABLES. Although the most important causal factor in PTSD is the traumatic event itself, individuals differ in the intensity of their cognitive and emotional responses to trauma; some persons appear to be more vulnerable than others. In some cases, this greater vulnerability is related to temperament or natural disposition, with shy or introverted people being at greater risk. In other cases, the person’s vulnerability results from chronic illness, a physical disability, or previous traumatization—particularly abuse in childhood. As of 2001, researchers have not found any correlation between race and biological vulnerability to PTSD.
- Traumatic stressor: The patient has been exposed to a catastrophic event involving actual or threatened death or injury, or a threat to the physical integrity of the self or others. During exposure to the trauma, the person’s emotional response was marked by intense fear, feelings of helplessness, or horror. In general, stressors caused intentionally by human beings (genocide, rape, torture, abuse, etc.) are experienced as more traumatic than accidents, natural disasters, or “acts of God.”
- Intrusive symptoms: The patient experiences flashbacks, traumatic daydreams, or nightmares, in which he or she relives the trauma as if it were recurring in the present. Intrusive symptoms result from an abnormal process of memory formation. Traumatic memories have two distinctive characteristics: 1) they can be triggered by stimuli that remind the patient of the traumatic event; 2) they have a “frozen” or wordless quality, consisting of images and sensations rather than verbal descriptions.
- Avoidant symptoms: The patient attempts to reduce the possibility of exposure to anything that might trigger memories of the trauma, and to minimize his or her reactions to such memories. This cluster of symptoms includes feeling disconnected from other people, psychic numbing, and avoidance of places, persons, or things associated with the trauma. Patients with PTSD are at increased risk of substance abuse as a form of self-medication to numb painful memories.
- Hyperarousal: Hyperarousal is a condition in which the patient’s nervous system is always on “red alert” for the return of danger. This symptom cluster includes hypervigilance, insomnia, difficulty concentrating, general irritability, and an extreme startle response. Some clinicians think that this abnormally intense startle response may be the most characteristic symptom of PTSD.
- Duration of symptoms: The symptoms must persist for at least one month.
- Significance: The patient suffers from significant social, interpersonal, or work-related problems as a result of the PTSD symptoms. A common social symptom of PTSD is a feeling of disconnection from other people (including loved ones), from the larger society, and from spiritual or other significant sources of meaning.