You’ve found rolling papers in their bag. You’ve caught an unfamiliar smell on their clothes. Or they’ve told you outright. Right now you’re probably feeling a mix of fear, anger and guilt. The first thing I need to tell you is that what you do in the next few hours matters more than what you do over the next few weeks. Before you react, breathe.

I’ve been working with teenagers who use cannabis and with their families for more than a decade. If you’ve landed on this article, you’re probably trying to understand what’s happening and what you should do. What follows is what I tell parents in the first session, adapted to something you can read quietly at home.

Understand before you react

A parent’s first instinct, when they discover their child is using, is usually to read it as rebellion, disobedience or personal betrayal. It almost never is. A teenager who smokes cannabis isn’t doing it “against you”. They’re doing it for reasons that, from inside their world, make sense: curiosity, peer pressure, wanting to belong, or (and this is the one that most deserves attention) trying to regulate something inside them that they don’t know how to handle anymore.

That doesn’t make it fine. But it changes the starting point of the conversation.

If you treat it as a personal offence, your teenager shuts down. If you treat it as a signal you need to understand, you have a conversation that can actually happen.

There’s another piece of context worth keeping in mind. Today’s teenagers live in a hyperstimulated environment, with constant exposure to social media, academic and social pressure that’s hard to sustain, and fewer moments of quiet and boredom than any previous generation. A lot of adolescent use is an attempt to find a gap where nobody is demanding anything of them. That doesn’t excuse it. But if you don’t factor it in, the conversation you’re about to have will be missing something important.

What the data says

Most teenagers who try cannabis don’t develop a problem. They try it, weigh it up and move on. But a significant proportion do develop regular use that affects their academic performance, their relationships and their mental health.

The useful question, then, isn’t whether they’ve tried it. The useful question is where your teenager sits within that distribution. To know, you need to ask yourself:

How often are they using, as far as you know?
Are they using in a group or alone?
Has their schoolwork, their mood or their friend group changed?
Are they using cannabis to manage anxiety, sadness or stress?

Those four answers draw the real picture, which can range from casual experimentation to a pattern that needs immediate clinical attention.

Signs the use isn’t occasional

There’s a difference between trying something once and having built use into the routine. These are the signs that, in my therapeutic work, tend to indicate the second has happened:

Behavioural changes. Irritability that wasn’t there before, growing secrecy, lies about where they are or who they’re with, dropping activities they used to enjoy.

Falling academic performance. Grades slipping, absences, loss of interest in studying. Cannabis affects working memory and concentration, and in a still-developing brain the effects are sharper and last longer.

Change of social circle. Long-term friends disappear from the story. New ones show up, usually ones they don’t bring home. The new group tends to be the one that uses.

Use as a refuge, not a party. If your teenager smokes to “relax”, to sleep, to “stop thinking”, cannabis has stopped being a social experience and become an emotional regulation tool. This is the most serious one.

When a substance starts doing that job, the underlying problem isn’t cannabis anymore. It’s what’s underneath.

What to do when the conversation lands on you

Talk, don’t interrogate

Find a calm moment. Not the second they walk in the door, not in the middle of making dinner, not in front of siblings, not in the heat of the moment. “I found this and I’m worried” opens a door. “Care to explain what this is?” closes it before it starts.

Listen without interrupting

This is harder than it sounds. You’ll want to correct, clarify, explain why they’re wrong. Hold it. What you need from this first conversation is information, not obedience. Only if your teenager feels genuinely heard will you get honest answers from that point on.

Don’t downplay or catastrophise

“I smoked when I was young and I’m fine” downplays a real concern, especially since today’s cannabis has much higher THC concentrations than the cannabis of twenty or thirty years ago. “You’re going to ruin your life” exaggerates and costs you credibility. The truth is in the middle: cannabis use in an adolescent brain carries real, well-documented risks, and deserves to be taken seriously without resorting to scare tactics.

Set limits without negotiating the non-negotiable

Listening isn’t the same as accepting. You can be empathetic and firm at the same time: “I understand there’s pressure, and I appreciate that you’re telling me. This isn’t something we’re okay with, and we’re going to work out together how to deal with it.” Teenagers need clear limits. Not in order to like them. As the frame they move inside.

Ask for professional help if the pattern is in place

If use is weekly or more frequent, if there are clear behavioural changes, or if you suspect anxiety, sadness or something else is sitting underneath, see a professional. A psychologist who specialises in adolescents and addiction can:

Assess clinically whether there’s a problem and how serious it is.
Work with your teenager individually, in a space without judgement where they can say things they can’t say to you.
Work with you and the family to improve communication and rebuild connection.
Identify and treat associated issues (anxiety, depression, ADHD) that often sit behind the use.

What almost never works

Based on years of therapeutic work, these are the strategies that, however tempting, rarely help:

Searching their room and phone. It destroys trust and turns your home into a warzone. The information you get that way will cost you more than it’s worth.
Threatening to throw them out. It creates fear, not change. And sometimes it accelerates exactly the break you were trying to prevent.
Trying to be their mate. Your teenager needs a parent, not another friend. There are moments when someone has to have real authority and real warmth at the same time.
Waiting for it to pass on its own. When use is regular, it rarely does. The longer it continues, the more the pattern consolidates.

When to seek help urgently

Seek professional attention as soon as possible if:

Your teenager is using daily.
They’ve had episodes of severe anxiety, paranoia or derealisation after using.
They’re mixing cannabis with alcohol or other substances.
They’re showing clear signs of depression: total withdrawal, neglecting hygiene, thoughts of self-harm.

In those cases, time matters.

You aren’t failing

Discovering that your teenager smokes cannabis doesn’t make you a bad parent. It doesn’t make them a bad person. It’s a more common situation than is openly discussed, and when addressed early and with the right people, the outlook is very good.

What never works is facing it in silence and alone. Shame is one of the reasons these problems take so long to reach a consulting room, and one of the ones that does the most damage in the meantime.

My teenager smokes cannabis: what to do as a parent