Are poor grades a sign of cannabis use?

Poor grades alone do not prove cannabis use. They can, however, be a warning sign, especially when the decline sets in suddenly and other changes are added. Anyone who looks at these signs together is more likely to recognise whether a conversation is needed.

Why cannabis can affect school

Cannabis affects functions that are important for learning. The BIÖG describes how frequent cannabis use disrupts concentration. According to the same prevention website, this can also lead to problems at school and in training. The BIÖG also notes that tasks and appointments can easily be forgotten, because memory works less well. In the worst case, a school or vocational qualification is at risk.

The BIÖG names this risk for young people who use cannabis regularly. Whether cannabis plays a role for your child cannot be recognised from grades alone. That is a reason not to judge hastily.

What is documented about learning

Several statements from prevention work are well documented:

• Early start: According to drugcom, an early start to use results in lasting impairments of cognitive performance.
• Recovery after stopping: In a study with 88 participants aged 16 to 25, memory improved as early as the week after the last use. According to drugcom, it is unclear how lasting these changes are.
• Brain in development: According to the BIÖG, the young brain is in an important phase of development.

The research is not yet conclusive. Anyone who discusses the topic with their child should therefore not suggest that every drop in performance can clearly be traced back to cannabis. A sentence such as “I am not sure whether it is because of cannabis. I notice that you have changed” is honest and open.

Poor grades have many causes

A performance crisis can have many reasons. Some causes lie at school, others in private life, and often several act together. It therefore makes sense to ask questions before looking for an answer:

1. Has the situation in class changed, for example through a change of teacher or a conflict with classmates?
2. Is your child sleeping differently than before, and when do they go to bed?
3. Is there pressure from outside, for example from expectations, exams or a change of school?
4. Does your child have less contact with the friends they used to spend time with?

These questions serve to complete the picture. They do not amount to a diagnosis.

Warning signs in the bigger picture

A pattern is more meaningful than a single grade. You should pay attention when several of these changes occur together:

• Grades drop noticeably within a short time, and performance fluctuates strongly.
• Your child is absent from school more often or arrives late.
• They withdraw, react irritably or lose interests they once had.
• They argue more often with friends or within the family, or change their circle of friends.
• There is a smell of smoke or cannabis, or they carry items that go with it.

With patterns like these, a conversation matters more than any suspicion. Where cannabis is concerned too, what counts is whether the child dares to talk.

How the conversation can go well

Begin with an observation you can back up, and ask an open question: “I have noticed that your grades have got worse over the last few weeks. How are you doing with it?” Then listen without judging straight away. Only once it is clear what is going on does the question about cannabis come up, and then in a factual way.

If your child says they have problems with learning, you can think together about who at school can help. The article How does the school support parents in cannabis cases? explains how schools can help.

When outside help makes sense

If the drop in performance continues, if your child uses cannabis regularly or if you are unsure how to react, specialist advice makes sense. The parents' helpline of Nummer gegen Kummer can be reached on 0800 111 0 550. For questions about addiction and drugs, the Sucht & Drogen Hotline is available on 01806 313031. Advice in person can also help you place the situation in context.

Contact persons at school

Ask at school who is responsible for students in difficult situations. Often this is the class teacher, sometimes a school counsellor (Beratungslehrkraft) or school social work. There you can describe what you observe and ask what the school sees. It helps to stay concrete: which subjects are affected, since when has something changed, and are there absences?

At the same time, do not expect the school to catch your child alone. The school can be a point of contact, but the most important place for conversations remains the family. If you feel that a conversation at home is getting nowhere, advice can help bring parents, child and school into conversation.

What you can do now

1. Note since when the grades have changed, and which other changes you notice.
2. Raise the subject before you assume a cause.
3. Speak with the class teacher if you have the impression that the school sees something you do not see.
4. Seek advice if you have observed two or more of these warning signs over a longer period.

A useful addition to this article is What does a new circle of friends mean when cannabis is used? It covers another warning sign that often appears together with poor grades.