Miley Cyrus celebrated her 19th birthday

Miley Cyrus
Miley Cyrus celebrated her 19th birthday recently with a cake--supposedly a Bob Marley cake. When she saw it, the singer/actress said, "You know you're a stoner when your friends make you a Bob Marley cake. You know you smoke way too much [expletive] weed."

And therein lies the latest video-spawned drug-related controversy about Cyrus, who last year appeared on grainy video smoking what she later said was salvia. She has since admitted the incident was a mistake, but the latest video has people wondering if the birthday quips suggest where there's smoke, there's marijuana.
Miley Cyrus
Miley Cyrus
If Cyrus is going down the pot path (and we have no indication she is, for the record), she may want to be aware of some recent studies on the health effects of marijuana.

Cyrus may be part of a trend, one reported on in 2010 by Monitoring the Future, an annual national survey looking at attitudes, behavior and values of teens. The group reported that marijuana use is up among adolescents after declining in the previous decade.

The fallout? Teens who are heavy marijuana users could experience withdrawal symptoms similar to those of some adult pot users. Research published in a 2005 issue of the journal Drug and Alcohol Dependence surveyed 72 serious marijuana users age 14 to 19 who were in outpatient treatment for substance abuse.

Reported withdrawal symptoms included aggression, anxiety and irritability, and almost two-thirds of the teens said they suffered four or more symptoms. More than one-third said they experienced four or more symptoms on a moderate to severe level.

A 2009 study in the journal Chemical Research in Toxicology found that marijuana may not be the trouble-free drug some think it is. Scientists looked at the effects of condensed tobacco and marijuana smoke samples on cultured animal cells and saw there was substantially more damage to cells and DNA produced by marijuana than tobacco smoke. Tobacco smoke, however, caused harm to chromosomes and marijuana smoke did not.

Lung and some other cancers may not be linked to marijuana smoking. A study presented at the American Thoracic Society's international conference in 2006 looked at the smoking habits of 611 people who developed lung cancer. Researchers discovered that those who smoked marijuana, even frequently, were at no greater risk of lung, head and neck cancer than those who smoked less pot or none at all. A correlation was found between tobacco smoking and cancer--80% of people with lung cancer and 70% of people with head and neck cancer smoked tobacco.

For those worried that marijuana is a gateway drug, one study found it might not be. A 2010 study in the Journal of Health and Social Behavior surveyed 1,286 young adults and found a moderate relationship between using marijuana in the early teen years and use of other illegal drugs in early adulthood. But this link weakened when researchers adjusted for stress and life-related issues.

When they did, those who didn't graduate from high school or go to college had a higher risk of smoking marijuana as teens and using other illegal substances as young adults. Another predictor of later drug use was being unemployed after high school. But, once the stress of finding a job weakened, so did the relationship between using marijuana and other illegal drugs.
Miley Cyrus
Miley Cyrus
Miley Cyrus
Miley Cyrus