Pubdate: Thu, 09 Feb 2006
Source: Daily Trojan (U of Southern CA Edu)
Copyright: 2006 Daily Trojan
MARIJUANA STUDY DISPELS DRUG'S LINK TO DEPRESSION
The study's results show marijuana users are less depressed than non-users.
A recent study co-authored by a USC College researcher has discovered that there is no real link between regular use marijuana and symptoms of depression, dispelling a widely held assumption regarding the drug's use. Tom Denson, a USC doctoral candidate in psychology worked with Mitch Earleywine, an associate professor at the State University of New York, Albany, in conducting the study and writing the report. To Denson's surprise, the study found marijuana smokers to be less depressed than their non-smoking counterparts. The study was reported in the scientific medical journal "Addictive Behaviors" in June 2005. Earleywine was previously an associate professor at USC and the author of "Understanding Marijuana."
In addition to the report he co-authored with Denson, Earleywine has recently conducted and published three other studies on marijuana. In running the study, Denson and Earleywine contacted frequent users of marijuana and a smaller control group of non-users through the Internet. The test subjects completed Web-based surveys to gauge the level of marijuana use and researchers gauged depression levels using a scale developed by the Center for Epidemiologic Studies. Participants were categorized into those who consumed marijuana daily, once a week or less, or never in their lives. The survey also grouped subjects into various degrees of symptomatic depression ranging from none to severe.
Through the Internet, researchers were able to reach even those who might have been reluctant to be quizzed in person or on the phone. "We had nearly 4,500 respondents - the largest study of its kind," Denson said. The findings concluded that those who used marijuana had a less depressed mood, more positive effect and fewer somatic complaints than non-users, according to the report.
Overall, recreational and medicinal marijuana users were less depressed than non-smokers, but in a separate analysis, medicinal users reported more depressed mood and more somatic complaints than recreational users. Denson cited ambiguity in the scientific literature as to whether marijuana was associated with increased risk of depression as the initial motivation for conducting the study. "Numerous studies had found no link ( between marijuana use and depression ) while other studies found weak relationships between use of the drug and depression. We had initially suspected that these weak relationships may be due to the inclusion of medical users who may be rightfully depressed about their illness," Denson said.
Denson added that on another level, the researchers wanted to test whether marijuana users were really afflicted with "amotivational syndrome," as government-sponsored public service announcements frequently claim. "There is a tendency to associate the drug with an 'amotivational syndrome' in which marijuana users are presumed to be made apathetic and lazy due to the drug's effects," Denson said. "Our data and other research do not support that notion." Denson said college students who smoke marijuana receive comparable grades to those who abstain. Although the statistics for USC is unavailable, a study by the Harvard School of Public Health found that 15.7 percent of American college students had smoked marijuana in the past month. The study's findings on marijuana and its effects on depression contradict statements made recently by government officials.
In a May 3, 2005 release from the White House Office of National Drug Control Policy, director John Walters wrote, "Marijuana use, particularly during the teen years, can lead to depression, thoughts of suicide and schizophrenia." In response to the statements made by Walters, Rob Kampia, executive director of the Marijuana Policy Project in Washington, D.C., argued that "science should be used to inform policy, not manipulated to scare the public," according to the group's Web site, www.mpp.org.
When asked what the controversial results of the study meant for college students and current users, Denson's answer was straightforward. "It's probably not a good idea to start smoking marijuana if you never have. However, if you do smoke marijuana, even every day, you are not putting yourself at any additional risk for depression," he said.