Bundestag decision: Cannabis becomes legal – what does science say?

From April onwards, adults in Germany will be able to legally smoke weed. The Bundestag decided that. A scientific assessment of the pros and cons.

An estimated four and a half million people in Germany use a joint at least occasionally. You should be happy that this will be legal from April. But there are also reasons that speak against release. After all, cannabis is an addictive drug. From a scientific perspective, what are the pros and cons of legalizing cannabis?

Cannabis consumption changes the brain

Cannabis is often trivialized and underestimated. In young people in particular, consuming weed can lead to permanent changes in the brain – this was shown by a study of 800 young people in 2021. In behavioral tests, the young users had difficulty concentrating and were more impulsive. Such a change in the brain can occur until it is fully developed – which is not until the age of around the mid-20s. Until then, the risk from cannabis consumption is significantly increased. This means that even 18-year-old consumers can still cause lasting damage to their brain.

Psychological consequences of cannabis consumption

Cannabis can be addictive. Experts estimate that around ten percent of people worldwide who use cannabis are addicted. Cannabis addiction can lead to physical withdrawal symptoms, but the social and psychological consequences are often serious.

Frequent cannabis consumption can trigger psychosis. However, it is controversial whether it is the only factor that leads to psychosis in those affected. Most regular users do not develop psychosis. But the risk of other mental illnesses such as depression or anxiety disorders is also increased in people who used cannabis in their youth.

Legalization could enable safer consumption

With the approval, however, risks posed by illegally sold cannabis could be avoided. One problem is the increasing content of tetrahydrocannabinol (THC), the psychoactive substance in these varieties, which causes increasingly strong intoxicating effects. There are many scientific indications that this cannabis can be particularly addictive to younger people. Researchers were also able to show that people suffering from psychosis usually frequently consumed cannabis with a lot of THC.

In addition, illegally sold cannabis can be contaminated: hairspray, glass and lead are added to make the flowers prettier and heavier. Some illegal cannabis is mixed with synthetic cannabinoids. They can increase the effects of the drug and make it uncontrollable. The side effects range from vomiting to delusions to circulatory collapse.

Many consumers don’t know what cannabis they are consuming, explains toxicologist Volker Auwachter from the University of Freiburg SWR: “Consumers cannot differentiate between ‘normal’ cannabis and this manipulated material because they do not differ in appearance, smell or taste.” Synthetic cannabinoids are significantly more dangerous than THC, both in terms of acute effects and medium-term consequences, according to Auwachter.

More offers of help thanks Decriminalization

Clearance can also make it easier for addicts to access support services. Experts believe that if consumers no longer have the feeling that they are acting criminally, they may be more willing to seek treatment. Legalization could also ensure better drug prevention. Young people could be educated differently at school and possibly talk more openly about consumption with their parents or in therapy.

Greater consumption through legalization?

It is controversial whether release will lead to greater consumer behavior among the population. Consumption among adults in Canada has barely increased since legalization at the end of 2018, and it has even declined slightly among adolescents and young adults. Studies have not yet confirmed that cannabis is a gateway drug to harder drugs.