Within 3 months, Ms. M’s symptoms have improved and no longer meet DSM-IV-TR criteria for PTSD. She continues to struggle with insomnia, affective constriction, and a sense of social isolation—symptoms that often remit slowly, if at all, in trauma victims despite good treatment. She stays in therapy to work on confronting her fears and finding meaning in her experience.
2. Physical exercise
Exercise is a type of active coping that diminishes negative emotions caused by stress. Regular exercisers report less-frequent depression,14 and exercise has been shown to improve clinical depression in adults.15 Exercise builds physical and emotional hardiness, lifts mood, and improves memory. It produces these health benefits by:
- releasing endorphins and serotonin precursors
- attenuating basal hypothalamic-pituitary-adrenal axis activity
- promoting expression of neurotrophic and neuroprotective factors.16
CASE CONTINUED: Learning to self-soothe
Ms. M learns to read children’s stories to help her fall asleep at night and stave off nightmares. She takes up yoga to combat residual anxiety. She also resumes singing in her local chorus, which includes riding the subway home from rehearsals at 10 pm.
Resilience: Preventive medicine for posttraumatic stress?
Resilience is the ability to maintain normal functioning despite adversity. It can be viewed as the successful operation of “basic human adaptational systems.” Conversely, depression and posttraumatic stress disorder (PTSD) may be understood, in part, as failure to adapt to stress.
Risk factors for PTSD. Traumas with the highest risk for psychopathology are severe, unpredictable, or uncontrollable and those that involve loss of property or (especially) a loved one, danger to self, or physical injury. PTSD risk also is increased by the cumulative effect of multiple, severe, uncontrollable traumas and personal factors such as:
3. A Positive outlook
Depressed individuals tend to view their problems as permanent and pervasive, whereas those who are resilient see adversity as temporary and limited in scope.
Role of dopamine. Humor and positive emotions have been linked to the dopaminergic reward mechanism in the mesolimbic circuitry. Dopaminergic neurons in the ventral tegmental area fire when a reward is received (Table 2); firing increases when a reward is unexpected or greater than expected. These same neurons release less dopamine when rewards are smaller than expected or not received at all.
Optimists are thought to have a robust dopaminergic response to reward, which is either hypersensitive to rewards and/or resistant to dysregulation under stressful (unrewarding) conditions.20
Mastering childhood adversity may ‘inoculate’ against future stress
Undertaking and mastering difficult tasks appears to be an effective way to increase resilience to stress. The “stress inoculation” hypothesis provides a plausible explanation for the observation that children who learn to cope with stress become hardy adults.
Men and women who successfully managed stressful situations in childhood—including death or illness of a parent or sibling, family relocation, and loss of friendship—are more resistant to adulthood stressors, such as divorce, death or major illness of a loved one, and job loss.8 Conversely, individuals who experienced extreme childhood stress that they could not control or master—such as physical and/or sexual abuse—may be more vulnerable to future stressors.
Like vaccination? Organisms develop immunity after exposure to a pathogen’s attenuated form; similarly, they may develop resistance to stress after being exposed to and overcoming mild stressors.9 Immunity to stress is not specific to the type of stressor first encountered; early exposure to manageable stress appears to enhance resilience to many adverse experiences.
Neurobiology of resilience. In a series of studies, Special Forces soldiers had higher blood levels of 2 stress-protective hormones—neuropeptide Y (NPY) and dehydroepiandrosterone (DHEA)—immediately after high-stress interrogations than did soldiers who received lessintensive training.10 These hormones also correlated with better performance under stress.
NPY and DHEA help keep the stress response in check by inhibiting release of norepinephrine, cortisol, and other stress-related hormones under high-stress conditions.11 To what degree genetics, development, and/or training enhance NPY and DHEA release is not clear.