White House Warns of Pot-Depression Link

White House officials issued a report Friday citing growing
evidence of a connection between marijuana use and depression in teens .

The White House reports that 25% of adolescents who have been depressed at
some point in the past year have used marijuana, compared with 12% of
non-depressed teens. Researchers have long known that drug and alcohol use tend
to go hand-in-hand with mental illnesses. Part of the reason is that people
with depression and other illnesses
often "self-medicate" to ease their symptoms.

But officials are also pointing to evidence that marijuana could actually
make depression symptoms worse in
teens. The report points to several studies concluding that teens already
showing signs of depression are more likely to have severe depression,
psychosis, or suicidal thoughts if they use marijuana.

"Marijuana is not safe and it's not a solution for depression," John
P. Walters, director of the White House Office of Drug Control Policy, told
reporters.

Drug officials say they've had a hard time convincing parents, many of whom
smoked marijuana as a sort of rite of passage in the 1960s and 1970s, that the
drug is more potent and more dangerous for young people than it once was.

"Everywhere else we have consensus," Walters said, referring to
other illegal drugs. "Marijuana is one where we kind of don't have
consensus," he said.

"It's gone from a very mild drug (a few decades ago) to a very serious
medication for the same amount of smoking," said Larry Greenhill, MD, who
is president-elect of the American Academy of Child and Adolescent
Psychiatry.

The brain has built-in receptors, known as cannabinoid receptors, which
respond to marijuana's active ingredients. Nora Volkow, MD, who heads the
National Institute on Drug Abuse, said researchers have increasing evidence
that those same receptors also regulate the brain's stress response.

Heavy marijuana use could make the cannabinoid receptors less responsive
over time, making the brain less equipped to handle stress and more vulnerable
to depression, Volkow says.

Causal Link?

The White House report also cites studies showing that adolescents who smoke
marijuana face up to a 40% chance of developing mental disorders later. The
report concludes that "using marijuana can cause depression and other
mental illnesses."

Though the link between drug use and depression is strong, a causal link has
not yet been established, Volkow said.

"Based on the data, I cannot tell you unequivocally marijuana causes
depression," Volkow said.

"I think at this stage, that research is early," Walters said.
"In short, marijuana makes a bad situation worse."

Does Report Go too Far?

Michael Fendrich, a psychologist who directs the Center for Addiction and
Behavioral Health Research at the University of Wisconsin, said the White House
report "overreaches" in some of its conclusions.

"It's kind of sensationalist," Fendrich told WebMD. He said some
studies have found a small increased risk of psychosis after heavy marijuana
use.

But most long-term studies have been "very tentative" about linkages
between marijuana and depression, Fendrich said. While the association between
marijuana use and worsening depression makes "some theoretical sense",
most studies have not been able to single out the drug as an independent risk
factor, he said.

"Drug use is part of a whole menu of risks that kids are facing right
now. And there are a lot of things kids can do to self-medicate, including
drinking, which is legal and probably a lot easier to access," he said in
an interview.

By Todd Zwillich
Reviewed by Louise Chang
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