Smoking pot as a teen may lead to psychosis later on in life. Cannabis is described as an “illicit drug” and is the most used in this category worldwide. Interesting enough, it is not clear whether the link between cannabis and psychosis is direct, or whether it is because people with psychosis use cannabis to self medicate their symptoms.

A Dutch team, where cannabis usage is legal in their country, set out to investigate the association between cannabis use and the incidence and persistence of psychotic symptoms over 10 years. However, the study took place in Germany and involved a random sample of 1,923 adolescents and young adults aged 14 to 24 years.

Incident cannabis increased the risk of later incident psychotic symptoms by almost half, even after accounting for factors such as age, sex, socioeconomic status, use of other drugs, and other psychiatric diagnoses.

Outstanding is the finding that those persons that were using cannabis use at the start of the study, continued use of cannabis over the ten year study period increased the risk of persistent psychotic symptoms.

The authors summarize:

“These results help to clarify the temporal association between cannabis use and psychotic experiences. In addition, cannabis use was confirmed as an environmental risk factor impacting on the risk of persistence of psychotic experiences.”

The legality of cannabis has been the subject of debate and controversy for decades. Cannabis is illegal to consume, use, possess, cultivate, transfer or trade in most countries. Since the beginning of widespread cannabis prohibition around the mid 20th century, most countries have not re-legalized it for personal use, although more than 10 countries tolerate (or have decriminalized) its use and/or its cultivation in limited quantities. Medicinal use of cannabis is also legal in a number of countries, including Belgium, Canada, the Netherlands, Czech Republic, Israel and 15 states of the United States.

The name marijuana (Mexican Spanish marihuana, mariguana) is associated almost exclusively with the plant’s psychoactive use. The term is now well known in English largely due to the efforts of American drug prohibitionists during the 1920s and 1930s. The prohibitionists deliberately used a Mexican name for cannabis in order to turn the US populace against the idea that it should be legal by playing to negative attitudes towards that nationality according to the 1937 Marihuana Tax Act.

In the United States, a September 2009 article in Fortune Magazine notes that President Barack Obama’s stance regarding marijuana, expressed by the U.S. Attorney General’s Office, has all but decriminalized its use in the United States. The U.S. Attorney General, Eric Holder, confirmed at a press conference that his Office would no longer subject individuals who were complying with state medical marijuana laws to federal drug raids and prosecutions. The article likens Obama’s policy toward marijuana, in terms of its eventual outcome, to the Twenty-First Amendment of the U.S. Constitution, which repealed the federal prohibition on alcoholic beverage sales.

In 2010, Proposition 19, titled the “Regulate, Control, and Tax Cannabis Act of 2010”, qualified for the November California ballot. Rejected by 54% of voters, this initiative would have legalized the recreational use of cannabis and its related activities in the State of California. It would also have allowed local governments to regulate and tax the newly created cannabis market.

Sources: British Medical Journal and Fortune Magazine

Written by Sy Kraft, B.A.