DURHAM, N.C. -- Children often get past traumatic events without subsequently encountering posttraumatic stress disorder, researchers here reported.

PITTSBURGH -- Teenagers who believe that wealthy, successful people smoke are more likely to become smokers themselves, researchers here reported.

COLUMBUS, Ohio -- Boys with Duchenne muscular dystrophy are able to walk more than three years longer if they take daily corticosteroids, according to researchers here.

SEATTLE -- Hospitalized older patients spend too long flat on their back, a situation prompted at least in part by a hospital culture that discourages mobility, researchers said here.

SEATTLE -- Opioid-induced constipation in advanced cancer is relieved for more than half of patients within four hours by a subcutaneous injection of methylnaltrexone, researchers here reported.

SEATTLE -- Giving older type 2 diabetic patients a pedometer and a goal to meet may be enough to get them moving, researchers said here.

BETHESDA, Md. -- About one American in 10 has had a problem with legal or illegal drug use, according to researchers here.

SEATTLE -- Sex remains an important part of life for many older Americans even as they develop more sexual problems as they age, researchers here reported.

SAN FRANCISCO -- Reducing levels of one of the proteins involved in Alzheimer's disease appears to prevent some of memory loss and learning difficulties -- at least in experimental mice.

BELFAST -- Some men with diabetes have sperm that exhibit greater DNA damage than non-diabetics' sperm, researchers here said.

OULU, Finland -- Tonsillectomy is an effective remedy for adults with recurrent bouts of group A streptococcal pharyngitis, according to researchers here.

ZURICH -- Wearing protective clothing is better than using sunscreens to prevent skin cancer and hold off the aging effects of solar rays, said investigators here.

OTTAWA, May 3 -- The risk of heart disease increases in the presence of a common genetic variation carried by about 20% of Caucasians, according to two reports published online today in Science.

BOSTON -- Women who took estrogen before age 65 may not be at a higher risk of later dementia, as previously reported, said investigators here.

BOSTON -- Migraine headaches among veterans of combat in Iraq indicate a more than twofold risk for depression, post-traumatic stress disorder, and anxiety, reported military researchers.

BOSTON -- Heavy drinking takes a toll on brain size, with a shrinking effect equivalent to about one to two years of brain aging for every higher level of alcohol consumption.

BOSTON -- The risk of multiple sclerosis progression can be significantly reduced by starting patients on interferon beta-1b (Betaseron) before a diagnosis of MS is even confirmed, investigators reported here.

STOCKHOLM -- The risk of testicular cancer can be reduced if surgery for undescended testicles takes place before puberty, according to researchers here.

BOSTON -- Even amateur boxers risk brain damage from repeated blows to the head during a single fight, Swedish researchers reported here.

ATLANTA -- Cavities are on the increase among the pre-school set, indicates a report from CDC.