Extreme stressors such as trauma in combat, being a victim of assault or sexual abuse, or experiencing or witnessing a crime can lead to a form of stress that can last a lifetime.
In the United States, this condition, called post-traumatic stress disorder, or PTSD, has a lifetime prevalence rate of 6.8 percent (9.7 percent in women and 1.8 percent in men). ). It is characterized by intense fear, helplessness or horror, intrusive recollections of the traumatic event, avoidance and numbing, and hyperarousal. In addition, PTSD is associated with dysregulation of stress hormones, disordered sleep, and major depressive disorder. Military personnel are at elevated risk for exposure to trauma, so not surprisingly, they have higher prevalence rates compared to the general population.
Scientists have studied PTSD in depth and have learned that the very high levels of norepinephrine released in the brain during stress remain at heightened levels. Medications that work well for patients with PTSD have emerged from basic research into norepinephrine’s actions in different brain regions. The alpha-1 blocker prazosin, a drug used to lower blood pressure for more than 20 years, is now used to treat nightmares experienced with PTSD. People treated with prazosin include those with a very long-standing illness, such as Holocaust survivors. Beta-blockers such as propranolol also are being tested in individuals exposed to trauma, but these agents must be administered shortly after the trauma, before PTSD has been established, which brings up complex ethical issues. PTSD also is treated with antidepressant and atypical antipsychotic medications and psychotherapies, such as cognitive behavioral therapy or eye movement desensitization and reprocessing therapy.
The discovery of brain receptors for the benzodiazepine antianxiety drugs has sparked research to identify the brain’s own antianxiety chemical messengers. Benzodiazepines bind to GABA receptors and enhance responsiveness to endogenous GABA, the major inhibitory neurotransmitter in the brain. Indeed, recent studies have revealed alterations in certain GABA receptors in the central nervous system of patients with PTSD, effectively providing an additional neurochemical link between different anxiety disorders. This finding may lead to new ways to modulate anxiety disorders.