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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.
-If this study also included a functional neuroimaging procedure, then (compared to controls) patients with PTSD would be most likely to exhibit alterations in which of the following?Prefrontal cortexHippocampusAmygdala

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.
-If this study also included a functional neuroimaging procedure, then (compared to controls) patients with PTSD would be most likely to exhibit alterations in which of the following?Prefrontal cortexHippocampusAmygdala

Quizplus · Accepted Answer

11ecba2d_0cc3_8f04_a3bf_15127a5928f1_MD0008_00 In response to stress, the adrenal glands release stress hormones (eg, cortisol, epinephrine, norepinephrine), which have various effects throughout the body (eg, increased heart rate). Prolonged exposure to stress impacts the functioning of many systems, including the brain. The hippocampus, amygdala, and prefrontal cortex (anterior portion of the frontal lobe) are sensitive to stress hormones and demonstrate structural changes in response to chronic stress, such as what might be experienced with PTSD. (Number I) Prefrontal cortex: Chronic stress has been shown to decrease dendritic branching in areas associated with cognitive flexibility, resulting in reduced coping mechanisms. It also increases dendritic branching in areas associated with hypervigilance. (Number II) Hippocampus: Chronic stress has been shown to increase inflammation while decreasing dendritic branching and volume in the hippocampus. These physiological changes may inhibit learning and memory and produce emotional changes, such as anhedonia (decreased ability to experience pleasure). (Number III) Amygdala: Chronic stress changes the growth of dendritic spines and alters the excitability of neurons in the amygdala, leading to more anger, fear, and anxiety. Overall, chronic stress changes the brain in ways that fundamentally reduce one's ability to manage further stressors (ie, decreased coping mechanisms) while increasing anxiety and hypervigilance. Compared to controls, patients with PTSD would be likely to exhibit altered functioning of the prefrontal cortex, hippocampus, and amygdala. Educational objective: The hippocampus, amygdala, and prefrontal cortex demonstrate structural changes in response to chronic stress. Atrophy of the hippocampus inhibits learning and changes emotional responses. Changes in the dendrites of the amygdala are associated with increased anger, fear, and anxiety. Hypervigilance and poor coping skills are linked to changes in the dendritic branching of the prefrontal cortex.

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