HICAGO, Sept. 30 (AP) — The American Academy of Pediatrics has issued its first guidelines for treating attention deficit hyperactivity disorder, suggesting that stimulant drugs may be most effective but that behavioral techniques should also be used.

The guidelines appear in the October issue of the medical journal Pediatrics, which will be released Monday.

As many as 3.8 million school-age children, most of them boys, are believed to have attention deficit disorders. Symptoms may include a short attention span, impulsive behavior and difficulty sitting still.

The guidelines, which fall in line with those issued in recent years by the National Institute of Mental Health, were created in consultation with child psychiatrists and psychologists. They suggest that the evidence favoring medications like Ritalin is stronger than the evidence about behavioral therapy.

Symptoms improve in at least 80 percent of children on stimulants, and medication should be switched if it is not working, the guidelines say.

Critics say that many doctors and teachers turn to drugs like Ritalin as an easy fix and that their long-term effects are uncertain. The guidelines say any treatment should begin only after a diagnosis is certain and doctors, parents and teachers have discussed appropriate treatment goals.

The guidelines say drugs should be used with behavioral techniques, including time-outs for hitting. They call for rewarding children when they complete tasks, like homework.