In the latest survey, 42 percent reported depression, 21 percent difficulty concentrating and 18 percent trouble sleeping.

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The symptoms of the illness include a numbing of emotions, difficulty concentrating and exaggerated startled responses to events.

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People with frontal lobe damage caused by accidents often find difficulty concentrating and are more easily distracted, research shows.

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The symptoms generally start on the chest, neck and face, and can be accompanied by headache, nausea or difficulty concentrating.

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Hyperarousal symptoms include difficulty falling or staying asleep, irritability or outbursts of anger, difficulty concentrating, being hypervigilant and finally, demonstrating an exaggerated startle response.

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