The first national survey of children with attention deficit/hyperactivity disorder shows that nearly half of preschoolers are on medication for the condition, and more than a fifth were receiving neither of the recommended therapies.

American Academy of Pediatrics guidelines call for the use of behavioral therapy first with children younger than 6 because the long-term impacts of medications on developing brains are not well known. But the data show that 46.6 percent of the pre-school aged children with the disorder had taken medication alone or with behavioral therapy in the previous week, and 53.2 percent had used behavioral therapy in the previous year. Another 21. 4 percent received neither therapy.

The numbers also show that 15.3 percent of pre-schoolers were taking dietary supplements, though there are no proven dietary treatments for the disorder, said Steven Cuffe, chairman of the Department of Psychiatry at the University of Florida College of Medicine in Jacksonville and one of the study authors.

Brain scan may help detect CTE

A brain-scanning technique might one day help identify people with a disease linked to concussions in football and other sports, an illness now diagnosed only after death, a study suggests.

Scans of 14 retired football players at risk for the condition, called CTE, revealed deposits of abnormal protein in a pattern resembling that found at autopsy in the disease. CTE stands for chronic traumatic encephalopathy. It causes progressive brain degeneration in athletes and others who've had repeated concussions and other blows to the head. Symptoms include memory loss, confusion, aggression, depression and progressive dementia.

No cure is known. But the brain-scanning approach raises the possibility of detecting the disease early, when the chances would be greatest for success of experimental treatments, study authors said. It might also shed light on the disease and help athletes with decisions on retirement, said a study author, Dr. Julian Bailes, co-director of the NorthShore Neurological Institute in Evanston, Ill.

Pollution raises risk of stroke

Air pollution — even for just one day — significantly increases the risk of stroke, a large review found.

Researchers pooled data from 103 studies involving 6.2 million stroke hospitalizations and deaths in 28 countries. The analysis, published online in BMJ, found that all types of pollution except ozone were associated with increased risk for stroke, and the higher the level of pollution, the more strokes there were.

The reason for the effect is unclear, but studies have shown that air pollution can constrict blood vessels, increase blood pressure and increase the risk for blood clots. Other research has tied air pollution to a higher risk of heart attacks, stroke and other ills.

Combo may prevent injury in a fall

Exercise and vitamin D supplements may help prevent injurious falls in older adults, a randomized trial found.

Finnish researchers recruited 409 women ages 70 to 80 who were living at home. Neither vitamin D supplements nor exercise reduced the number of falls. But compared with the placebo without exercise group, those who took vitamin D alone were 16 percent less likely to be injured in a fall; the placebo and exercise group were 54 percent less likely to be injured; and those who exercised and took supplements were 62 percent less likely to be hurt.

The authors suggest that physical conditioning and vitamin D increase bone density, which could help prevent injury.

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