A new report from the Boston Public Health Commission indicates that heroin use may be declining in the Boston area, reversing a trend that has raised alarm about use of the drug in recent years.

The Boston Channel reported March 9 that the report, Substance Abuse in Boston, found that both requests for treatment and help-line calls involving heroin use fell in 2006. Heroin remains the top reason for both treatment admissions and help-line calls in the region, ahead of alcohol use.

"We're not sure exactly why we're seeing some indicators on heroin abuse improve, but we hope that we are seeing a trend that will continue," said John Auerbach, executive director of the Boston Public Health Commission.

However, the report also found that the average age of individuals seeking help for heroin was declining, which Auerbach said, "points to a higher need for enhanced prevention and treatment efforts targeted at young people."

The report said that use of drugs like oxycodone, cocaine and marijuana appears to have stabilized. "We need to redouble our efforts to focus on prevention and on increasing treatment options for those who are caught in the cycle of addiction," said Boston Mayor Thomas Menino.