Marijuana improves the thought process

study: Weed doesn't make you stupid

Vienna. The US has been promoting the fight against drugs for decades. Even so, two states - Washington and Colorado - legalized smoking cannabis, also known as marijuana, hash or weed, last November. A current study published in the US science magazine "Pnas" ("Proceedings of the National Academy of Sciences") now seems to give the supporters of the referendum a kind of confirmation of their choice.

Accordingly, contrary to the opinion held so far, cannabis use does not make you stupid. As recently as August 2012, a study reported that cannabis reduced the intelligence quotient (IQ). The Norwegian researcher Ole Rogeberg from the Ragnar Frisch Center for Economic Research in Oslo has now reviewed the original study. The result: It is not the consumption of marijuana that causes the IQ to decrease, but the social and economic circumstances of the test subjects' lives.

Disturbance of perception

One thing is clear and undisputed: the regular joint disturbs the short-term memory, the ability to concentrate and the attention of the person. Thought processes as well as the perception of stimuli such as smelling, seeing, tasting, touching or hearing or time are effects that are also desired by consumers.

In August 2012, the study by Madeline Meier from Duke University in the US state of North Carolina caused a sensation worldwide. At the time, there seemed to be definitive evidence that cannabis was causing long-term damage to the brains of teenagers. The data came from the so-called Dunedin study. A survey of 1,037 people in New Zealand from the time of their birth in 1972 and 1973 to the age of 38 years of regular health and psychological questioning.

The social conditions

The evaluation had shown an apparently linear relationship. The more and more regularly the participants claimed to have smoked hashish, the worse they did in the IQ tests. The researchers also attributed this to the neurotoxic, i.e. the nerve cell killing, effect of cannabis.

However, Rogeberg drew attention to the living conditions of the test subjects and their families - the most decisive factor for him. The social conditions, as shown by the Dunedin study, alone would be sufficient to explain the poorer performance in the tests - and also their increased cannabis use. According to the Norwegian scientist, the methodology of Meier's study was flawed and the conclusions were hasty.

"If the effects are more due to culture than to pharmacology, this must also be taken into account when making decisions about the political and legislative handling of this issue," explains Rogeberg.

Incidentally, in Austria cannabis is subject to the provisions of the Narcotics Act. Accordingly, anyone who acquires, owns, produces, imports, exports or transfers or procures cannabis to another must be punished. Although hashish use is legal per se, it is still criminalized. Mainly because this mostly goes hand in hand with illegal possession.

So even heavy cannabis use does not seem to pose a threat to general human intelligence. Temporary impairments, however, are undisputed - just as they occur with all chemical intoxicating substances. All the more surprising is the small extent of the effects - in contrast to other legal or illegal substances such as alcohol or cocaine.