Is cannabis a gateway drug?

The simple claim that cannabis inevitably leads to harder drugs is considered disproven by drugcom. Even so, studies show that early experiences of use are linked to later use of other drugs. Whether cannabis is the cause remains open. The answer to the question in the title is therefore: cannabis does not automatically lead to other drugs, although early use deserves attention.

Where does the gateway drug theory come from?

The idea of a gateway drug rests on a simple chain: whoever tries cannabis then tries harder substances. This chain sounds logical, but it does not fit the observations well. Drugcom cites figures: around 23 percent of Germans over 18 have ever used cannabis, but fewer than one percent of all adults currently use other drugs. Most people stop using cannabis at some point.

According to drugcom, drug initiation cannot be reduced to the influence of a single substance. Anyone who takes the question seriously therefore looks at the whole environment: family, circle of friends, school, everyday life and personal stresses.

What the research shows

• In almost all cases, tobacco was smoked before the first cannabis cigarette.
• A twin study found a 7.4-fold higher probability of later party drug use after early cannabis use.
• This study accounted for family circumstances. It did not account for the circle of friends.

The study compared twins: whoever had smoked cannabis before the age of 18 later took party drugs with a 7.4-fold higher probability than the siblings who were older than 18 at their first joint. The figure deserves a careful reading. It describes a comparative probability and does not say that every early user later takes party drugs. Nor does it say that cannabis is the cause.

Why cause and effect are hard to separate

Imagine two teenagers who hang out in the same clique. One tries cannabis early, the other does not. Both later take party drugs. Was the early cannabis use the cause, or did the clique influence both? Exactly this question remains open, because the study did not account for the circle of friends.

The assessment is therefore sober: early experiences of use are linked to later use. Whether they trigger it cannot be determined with certainty from this study. An animal study found changes in the reward centre of the brain in rats that received THC during adolescence. Drugcom considers doubts about whether this applies to humans to be justified.

An overview of the findings

Finding	What the sources say	Assessment
Gateway drug theory	Considered disproven by drugcom	No inevitable chain
Tobacco before cannabis	In almost all cases tobacco is smoked first	Shows early routes of use that develop
Twin study	7.4-fold higher probability of later party drug use	Association, no proven cause

What prevention makes of this

Drugcom names peers as an important influence: usually people from the circle of friends initiate use and ensure availability. The guide on the consequences of an early start explains in more depth which consequences for concentration and performance are involved.

Especially for young people, the following applies: the brain is still developing. The guide on the young brain explains how this is connected.

The role of tobacco

That tobacco often stands at the start of the consumption history is an important finding. Drugcom also names alcohol: the first intoxication experiences are usually made with alcohol. According to drugcom, the reason this order seems so fixed is not fully understood. Social conditions and the “image” of a substance probably play a role. More on this in the guide on mixed use with tobacco.

Clarifying terms: initiation, switch and use patterns

The term initiation describes the moment when someone tries a substance for the first time. This is to be distinguished from a switch, in which someone moves from one substance to the next. Both are often mixed up in public debate. Anyone who wants to answer the question correctly should look closely at which process is meant.

A use pattern describes how often and in which situations someone uses. A single attempt is something different from regular use over years. For prevention, therefore, the first puff is less decisive than whether a pattern develops that causes problems.

Common misunderstandings

Many people believe that anyone who tries cannabis is already on the way to harder drugs. However, this assumption does not explain why most people who try cannabis never turn to other illegal substances. Nor does it explain why others develop problems with substances without any early cannabis use.

A second misunderstanding concerns the figures. Anyone who reads a number like 7.4 quickly thinks of fate. The correct reading is this: the figure describes a difference between groups and says nothing about the future of one individual. Whoever reads the figure this way can assess their own situation more realistically.

Those who start early need different support

According to BIÖG, young people are far more at risk from cannabis than adults. Helpful is an environment that talks openly about use without shaming. Parents, teachers and friends can play a role. How such a conversation can succeed is explained in the guide on talking about cannabis.

Your own perspective also matters. Anyone who started early can ask whether their use still fits their goals today. This question is a tool for decision-making. It is no verdict on the person.

When help makes sense

Help makes sense if use strains school, training, friendships or health. Even if you notice that you can no longer control your use yourself, counselling is the right place. This applies regardless of which substance is in the foreground.

The Sucht & Drogen Hotline offers a confidential first conversation. Anyone who wants to know more about advice options will find orientation in the guide on professional help.

What parents and professionals should keep in mind

For parents and professionals the following applies: an open exchange with young people is a good starting point for starting a conversation early.

What you can do now

• If you are worried about a young person, talk openly about use, without making accusations.
• Pay attention to the environment: who uses, and in which situations?
• If you started early yourself, check your use with the self-test.
• If problems persist, a counselling service can help: find addiction counselling near you.

For a confidential conversation you can reach the Sucht & Drogen Hotline at 01806 313031. More on prevention and youth protection is available under Prevention and youth protection.