WEDNESDAY, Oct. 8 (HealthDay News) -- Wall Street's roller coaster ride is costing Americans more than money: It's costing them sleepless nights and a heap of emotional distress, experts say.

FRIDAY, July 4 (HealthDay News) -- The brains of people who suffer from anxiety and severe shyness may respond more strongly to stress and show signs of being anxious even in situations considered safe by others, say researchers at the University of Wisconsin School of Medicine and Public Health.

They studied brain activity, anxious behavior and stress hormones in adolescent rhesus monkeys. Those with the most anxious temperaments showed higher activity in a part of the brain called the amygdala, which regulates emotion and triggers reactions to anxiety.