Until what age is the brain still developing?

BIÖG writes that especially during puberty and even up to the age of 25, many important remodelling and maturation processes take place in the brain, which can be disrupted by cannabis. Drugcom describes that the brain matures from childhood into young adulthood. No exact birthday on which development ends is named. What matters is the age together with the question of when and how often someone uses.

This article explains what the development of the brain means for use and which age limits the law sets.

What BIÖG says about the young brain

The prevention agency BIÖG points out that the young brain is in an important phase of development. In this time, abilities such as planning, learning and impulse control are shaped. Cannabis use can influence this development, as BIÖG explicitly notes.

This statement has a practical consequence. Anyone who uses in youth meets the brain at a phase that is not yet complete. Use in later adulthood acts on a brain whose development has progressed further. That makes a difference, even though the specialist websites give no year for it.

Why a cut-off date is hard to name

Development is described as a long process that extends from childhood into young adulthood. No more precise age than “up to about 25” is given.

Anyone under 25 is, according to this information, still in a phase in which cannabis can disrupt maturation. BIÖG writes that young people should not use cannabis at all for health reasons.

The age limits in law

The Cannabis Act (KCanG) sets clear limits. Persons who have reached the age of 18 may possess a personal limit of 25 grams for own consumption under section 3(1) of the KCanG, and other amounts apply at the place of residence (section 3(2) KCanG). Under the law, possession is not permitted for anyone under 18.

An overview of the limits for possession can be found in the article From what age may you possess cannabis?.

Young adults between 18 and 21

A separate group applies to certain rules. Under section 1(2) of the Juvenile Court Act (JGG), young adults (Heranwachsende) are persons who are at least 18 and still under 21 at the time of the offence. The KCanG uses this definition, for example when cannabis is distributed by a cannabis association (Anbauvereinigung). For young adults there, a monthly limit of 30 grams and a THC content of no more than 10 percent apply (section 19(3) KCanG).

For young adults, stricter limits apply than for adults aged 21 and over.

What you can take from this for yourself

The most important question is how you assess yourself within this development. Concentration, planning and mood can change when use starts early or becomes regular. A look at school, training and friendships often shows whether something is shifting.

• Have you given up goals that were important to you in recent months?
• Does it feel harder to get excited about things that used to bring you joy?
• Do learning or planning feel noticeably harder for you?

Anyone who answers one of these questions with yes should speak with a trusted person or a counselling service.

What changes in the brain during this phase

BIÖG names as consequences for young people, among others, disturbed concentration, problems at school and in training, and an increased risk of mental illness.

Drugcom adds that changes to the cerebral cortex have been observed in young users, and that it has not been conclusively established whether THC causes them.

Why early decisions have lasting effects

Drugcom writes that there is convincing evidence that an early start in use has lasting impairments on cognitive performance. According to drugcom, it has not been conclusively established whether the brain of young people recovers after stopping.

How families and schools accompany this phase

Parents can talk openly about risks, and schools can support with counselling offers.

An overview of how to deal with the topic in the family is offered by the article Which rules make sense for families with cannabis?.

What you can do yourself if you are young

If you are under 18, the legal position is clear: possession and home cultivation are not permitted under the KCanG. Beyond that, your brain is currently in a phase in which learning, planning and habits are strongly shaped. That is a reason to make decisions consciously.

Consider what matters to you in everyday life: school, training, sport, friendships or hobbies. If cannabis pushes one of these areas aside, that is an early sign you should take seriously. A trusted person, school social work or a counselling service can help you classify this change.

If you are unsure how to handle the topic, you do not have to clarify it alone. You can reach the Sucht & Drogen Hotline anonymously on 01806 313031 (calls are charged, daily from 8 am to midnight).

When a pause makes sense

If you notice that learning, planning or remembering is harder, a break from use can help you assess the situation. A pause shows you how you feel without cannabis.

Questions about your own development

If you wonder whether use is affecting your development, a look at changes in your everyday life helps. Note how things are going at school or in training, how you sleep and how well you carry out plans. These observations are a simple basis for a conversation with a trusted person.

Where to get help

An addiction counselling service helps to classify your development and your use. The Deutsche Hauptstelle für Suchtfragen lists counselling services across Germany in the Suchthilfeverzeichnis. The exact wording of the definition of young adults is available at gesetze-im-internet.de.