Here are some of the latest health and medical news developments, compiled by editors of HealthDay:
Marijuana Linked to Teen Mental Health Problems
Teens who've reported being depressed at some point in the past year are more than twice as likely (25 percent) to have used marijuana than those who weren't depressed (12 percent), according to a White House Office of National Drug Control Policy report to be released Friday.
The paper also said that marijuana use by teens increases their risk of developing a mental disorder by 40 percent and that teens who use marijuana at least once a month for a year are three times more likely to have suicidal thoughts than those who don't use the drug, the Associated Press reported.
In addition, teens who smoke marijuana when feeling depressed are more than twice as likely as other teens -- eight percent compared with three percent -- to abuse or become addicted to marijuana, the report said.
The report authors analyzed data from about a dozen previous studies that examined marijuana use.
"Marijuana is a more consequential substance of abuse than our culture has treated it in the last 20 years. This is not just youthful experimentation that they'll get over as we used to think in the past," John Walters, director of the drug control policy office, told the AP.
Since 2001, marijuana use among American teens has decreased 25 percent. Currently, about 2.3 million children use marijuana at least once a month, according to the drug control office.
Southern Metro Areas 'Hotspots' for Teen Driving Deaths
The 10 worst "hotspots" for teen driving deaths are in the southern United States, according to an Allstate Insurance Company study that examined federal crash statistics for 50 of the nation's largest metro areas.
The worst metro areas for rates of fatal teen crashes are: Tampa/St. Petersburg/Clearwater, Fla.; Orlando/Kissimmee, Fla.; Jacksonville, Fla.; Nashville, Tenn.; Birmingham, Ala.; Phoenix; Kansas City, Mo. and Kan.; Atlanta; Charolotte, N.C.; and Louisville, Ky.
The five metro areas with the lowest rates are: San Francisco/Oakland, Calif.; San Jose, Calif.; New York City (including Long Island and northern New Jersey); Los Angeles; and Cleveland.
The study also found that the rate of fatal teen crashes in rural areas of the United States is double the rate in cities and suburbs -- 51.5 per 100,000 teens per year, compared with 25. 4 per 100,000.
"We feel that state and federal leaders should enact uniform national standards for graduated drivers licensing laws. Further, we must have better conversations with teens about safe driving and set good examples through our own good driving behavior," George Ruebenson, president of Allstate Protection, said in a prepared statement.
Campaign Seeks to Prevent Doctor Suicides
An estimated 300 to 400 U.S. doctors commit suicide each year, which has prompted the American Foundation for Suicide Prevention to launch an educational campaign designed to encourage troubled doctors to seek help.