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Post-traumatic stress disorder (PTSD) and generalized anxiety disorder (GAD) both involve an exaggerated response to everyday stressors and a heightened state of anxiety or arousal that can impede concentration and daily functioning. Both can be effectively treated with medication, including anxiolytics and antidepressants, and with therapy, the most effective of which is cognitive-behavioral therapy (CBT) . Psychologists believe that the unpredictable nature of stressors plays a key role in the development and persistence of both disorders. However, the response to predictable threats is believed to be normal.A study was conducted to investigate how individuals diagnosed with PTSD or GAD respond to predictable and unpredictable threats. Twenty patients with PTSD, 20 patients with GAD, and 50 control participants took part in the study. The groups did not differ significantly with respect to age or gender. The study involved two conditions, each three minutes in duration. During the first (predictable) condition, participants were shown a cue (red box) at random times while gazing through a viewing apparatus. The cue signaled the imminent presentation of various loud noises such as thunder or screaming, meant to induce fear. During the second (unpredictable) condition, the loud noise was presented randomly with no warning.The magnitude of the participants' startle response was measured by an eye blink reflex recorded with electrodes placed under the eyes (measured in microvolts [Table 1]) .Table 1 Mean Startle Response in Microvolts by Group and Condition
After the study, participants were asked to rate their subjective fear on a scale of 0 (no fear) to 10 (most fear) . The controls reported the least fear under both conditions. PTSD participants expressed greater fear than GAD participants during the unpredictable condition, but GAD participants reported greater fear than PTSD participants during the predictable condition.
C. Grillon, D. S. Pine, S. Lissek, S. Rabin, and M. Vythilingam ©2009 by Society of Biological Psychiatry.
-Which of the following best explains how long-term exposure to chronic stress could account for the physiological findings in Table 1?

Question

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Post-traumatic stress disorder (PTSD) and generalized anxiety disorder (GAD) both involve an exaggerated response to everyday stressors and a heightened state of anxiety or arousal that can impede concentration and daily functioning. Both can be effectively treated with medication, including anxiolytics and antidepressants, and with therapy, the most effective of which is cognitive-behavioral therapy (CBT) . Psychologists believe that the unpredictable nature of stressors plays a key role in the development and persistence of both disorders. However, the response to predictable threats is believed to be normal.A study was conducted to investigate how individuals diagnosed with PTSD or GAD respond to predictable and unpredictable threats. Twenty patients with PTSD, 20 patients with GAD, and 50 control participants took part in the study. The groups did not differ significantly with respect to age or gender. The study involved two conditions, each three minutes in duration. During the first (predictable) condition, participants were shown a cue (red box) at random times while gazing through a viewing apparatus. The cue signaled the imminent presentation of various loud noises such as thunder or screaming, meant to induce fear. During the second (unpredictable) condition, the loud noise was presented randomly with no warning.The magnitude of the participants' startle response was measured by an eye blink reflex recorded with electrodes placed under the eyes (measured in microvolts [Table 1]) .Table 1 Mean Startle Response in Microvolts by Group and Condition

After the study, participants were asked to rate their subjective fear on a scale of 0 (no fear) to 10 (most fear) . The controls reported the least fear under both conditions. PTSD participants expressed greater fear than GAD participants during the unpredictable condition, but GAD participants reported greater fear than PTSD participants during the predictable condition.
C. Grillon, D. S. Pine, S. Lissek, S. Rabin, and M. Vythilingam ©2009 by Society of Biological Psychiatry.
-Which of the following best explains how long-term exposure to chronic stress could account for the physiological findings in Table 1?

Quizplus · Accepted Answer

11ecba2d_0cc1_1e03_a3bf_8de6e42ad7b7_MD0008_00 The general adaptation syndrome (GAS), proposed by Hans Seyle, describes how the body reacts to stress that is acute or long-lasting. According to this model, there are three stages of the stress response: The alarm stage is the first few minutes of the stress response, during which the sympathetic nervous system prepares the body to act (ie, fight-or-flight response). Heart rate, respiratory rate, and blood glucose levels increase, and stress hormones (eg, adrenaline, cortisol) are released. The resistance stage can last for hours (eg, exercise), days (eg, final exams), or even months (eg, family death). During this stage, the body attempts to resist or address the stressor. Levels of stress hormones begin to return to normal. The body attempts to establish a new equilibrium. If stress continues over a prolonged period, the body enters the exhaustion stage, a state of arousal but with depleted energy. It is during this stage that chronic diseases (eg, high blood pressure, heart disease) can develop. The body is no longer able to resist the impact of stressors. The startle response to the unpredictable stressor elicited in control subjects was relatively mild, reflecting a normal alarm stage response to a low-threat stressor. The PTSD and GAD subjects demonstrated exaggerated responses to the unpredictable stressor that are best explained by chronically elevated stress levels and diminished ability to fend off stressors, characteristic of the exhaustion stage of GAS. (Choice B) In sociology, the Thomas theorem predicts that an individual's response or reaction to a situation is the result of her interpretation of the situation. In other words, our actions are based on our perception of reality. While this theory may address how PTSD and GAD participants interpret stressors, it does not directly consider the physiological impact of chronic stress, such as GAS. (Choice C) The Yerkes-Dodson law suggests that there is an optimal level of physiological or mental arousal at which performance is maximized; performance will decline with too little or too much arousal. For example, athletes tend to perform best when nervous but not too nervous. Table 1 reflects startle responses, not task performance, so this law does not best explain the results. (Choice D) The Hawthorne effect describes experimental subjects modifying their behavior or responses because they know they are being observed. This effect does not best explain the results in Table 1. Educational objective: The general adaptation syndrome suggests that the body's response to stress involves alarm (initial fight-or-flight response), resistance over time, and eventual exhaustion for very prolonged stressors, which may lead to the development of chronic disease.

Passage Post-Traumatic Stress Disorder (PTSD) and Generalized Anxiety Disorder (GAD) Both