Sick and Tired: Tracking paths to chronic fatigue

Stressful experiences and a genetic predisposition toward emotional turmoil contribute to some cases of chronic fatigue syndrome, two new studies indicate.

The investigations, published in the November Archives of General Psychiatry, add to growing evidence that several varieties of chronic fatigue syndrome (CFS) occur, each with distinct causes.

CFS affects roughly 800,000 people in the United States.