Study: Marijuana use did not cause depression and anxiety

Study: Marijuana use did not cause depression and anxiety

Marijuana users are not more likely to experience depression and anxiety
Generally, substances that can lead to addiction do not have a good reputation. Such substances are often assigned negative consequences. For several years, it was suspected that marijuana use could cause depression and other mental disorders. Researchers from Columbia University have now discovered in a large study that marijuana in adults is in no way responsible for such diseases.

There have been several studies in the past that have claimed that marijuana is responsible for some mental illnesses. A new study now disagrees. American scientists from Columbia University conclude that marijuana use in adults does not cause depression or anxiety disorders. The researchers published their results in the journal "JAMA Psychiatry".

New study disproves many older views
Marijuana use is often associated with the occurrence of mental disorders. Anxiety disorders and depression are thought to be caused by marijuana, scientists have claimed in the past. Some older studies have tried to demonstrate these negative effects. A new study has now shown that this view was wrong, say the doctors. Marijuana use does not trigger any of these mental illnesses in adults. The researchers say that neither depression, anxiety or bipolar disorders can be directly caused by the plant.

Scientists are examining the data from 35,000 adults
For their study, the doctors from "Columbia University" examined the records of almost 35,000 adults in America. These had participated in a national epidemiological survey on alcohol and other substances, the scientists explain. The researchers examined the prevalence of marijuana use among the study participants in 2001 and 2002. Then, a few years later, they checked whether the participants had developed mental disorders. The follow-up examination took place in 2004 and 2005, explain the doctors. A variety of disruptive factors were controlled, such as sociodemographic characteristics, family history, environmental influences, and psychiatric disorders in the past or present, the researchers continued. The experts concluded that marijuana use was not associated with an increased risk of developing depression or anxiety disorders.

Marijuana use increases the likelihood of alcohol and cigarette consumption
However, the study found a connection between marijuana use and later substance-related disorders, such as abuse and dependence on alcohol, tobacco and other drugs, the scientists explain. When people consume a drug frequently, they often use other substances. A good example of this is the classic combination of beer and cigarettes, the experts say. Marijuana users would be more likely to develop alcohol problems compared to drug-free people. In addition, those affected started smoking cigarettes twice as often, says lead author Mark Olfson of Columbia University.

Information sheets should be updated with the new facts
The current findings on mental health among cannabis users are very interesting given the contradictory views of previous research, the researchers explain. The study results are particularly important because a large part of the current literature on marijuana still contains statements that establish a connection between marijuana and depression. Such statements can be considered inaccurate in view of the new findings, the doctors explain. For example, the American Drug Enforcement Administration (DEA) claims in its marijuana fact sheet that the dangers and consequences of marijuana abuse are linked to depression. Depression is even mentioned fourteen times in the leaflet, and it is claimed that marijuana use can lead to depression in adolescents, adults, and even dogs, doctors say. Since such documents are used to inform politicians at the federal level, it is crucial that the latest and most accurate research results are reproduced, say the experts. This is especially true given the rapidly changing marijuana policy worldwide. (As)

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