WASHINGTON, Dec. 18 (AP) - Nearly three-fourths of Americans middle age and older support legalizing marijuana for medical use, according to a poll taken for AARP.

More than half of those questioned said they believed marijuana has medical benefits, while a larger majority agreed the drug is addictive.

AARP, whose 35 million members are all at least 50 years old, says it has no political position on medical marijuana and that its local branches have not chosen sides in the scores of state ballot initiatives on the issue in recent elections.

But with medical marijuana at the center of a Supreme Court case to be decided next year, and nearly a dozen states with medical marijuana laws on their books, AARP said, it decided to study the issue.

"The use of medical marijuana applies to many older Americans who may benefit from cannabis," said Ed Dwyer, an editor at AARP The Magazine, which will report on the issue in its March-April issue, scheduled to appear in late January.

Among the 1,706 adults age 45 and older who were polled in November, opinions varied along regional and generational lines and among the 30 percent of respondents who said they had smoked marijuana. AARP members represented 37 percent of the respondents.

Over all, 72 percent of respondents agreed "adults should be allowed to legally use marijuana for medical purposes if a physician recommends it." Those in the Northeast (79 percent) and West (82 percent) were more receptive to the idea than in the Midwest (67 percent) and Southwest (65 percent). In Southern states, 70 percent agreed with the statement.

Seventy-four percent of all those surveyed thought marijuana is addictive.