It started when he was 12, during a flight from Charlotte, N.C., to Savannah, Ga., in a 12-seater plane. The engine started smoking, and passengers began to panic. They landed safely, but the memory of that experience — the helpless feeling and his racing heart — was seared in his mind.
Overnight, Adam morphed into a fearful flyer. He would take the bus or train, anything to avoid planes. Adam is hardly alone. An estimated 12 percent of US adults have struggled at some point in their lives with a specific phobia, such as fear of flying, insects, or blood, according to the National Institute of Mental Health. Specialists say that most phobias are relatively easy to treat. The results of two recent studies, one involving the use of an anti-tuberculosis medication, and another involving sleep, show promise. Full story for BostonGlobe.com subscribers.