The signs fall into four areas: behaviour (secrecy, a new friend group, missing money), mood (irritability, low mood, loss of interest), body (changes in sleep, appetite, red eyes, neglected hygiene) and daily life (falling grades, skipping school, dropping activities). No single one is proof. It is a cluster of them, appearing together and lasting weeks, that should prompt a closer, calmer look.

Yes — and that is exactly why they are hard to read. Moodiness, new friends, wanting privacy and sleeping oddly are all ordinary parts of adolescence. The difference is intensity, duration and how many appear at once. One change on its own is usually just growing up. Several changes together, holding for weeks and pulling your teenager away from their normal life, are worth paying attention to.

Think weeks, not days. A bad mood over a rough weekend is normal. A steady shift in mood, sleep, friendships or school that persists for several weeks is a more meaningful signal. Duration matters because it separates a passing low patch from a genuine change in direction — whether that change is caused by drugs, by depression, or by something happening in their life.

Heavily. Withdrawal, irritability, changes in sleep and appetite, and losing interest in things once loved are common to both substance use and depression — and the two often occur together, each feeding the other. This is why the signs are a cue to find out what is going on, not to assume drugs. If your worry does not point to substances, the same changes still deserve attention.

Experimenting tends to be occasional, curiosity-driven and social — tried once or a few times, usually with friends, while daily life stays broadly intact. A problem looks different: use becomes regular, they seek it out on their own rather than only when it is around, and school, friendships, mood or health start to slip over weeks. Either way, a calm conversation is worthwhile.

There is no single right answer, and it is a judgement call between privacy and safety. Searching can damage trust badly if you are wrong, yet safety comes first when the signs are serious. Where you can, prefer an honest, direct conversation first. If you do feel you must look, being transparent about why — rather than doing it in secret — usually does less lasting harm to the relationship.

It can be, but on its own it means very little. Red eyes have countless ordinary causes: screens, lack of sleep, allergies, dust, swimming. Treat it as one small data point, not evidence. If red eyes come with unexplained smells, changes in behaviour, mood and sleep, and the pattern holds over time, then the cluster — not the red eyes alone — is what warrants a closer look.

Try not to lead with accusation, punishment or an interrogation. Confrontation usually triggers denial and pushes a teenager further away, exactly when you most need them to stay close. Avoid searching for a confession or issuing ultimatums in anger. The aim is to keep the door open: stay calm, stay curious, and make it clear you are on their side — even while you take the changes seriously.

Pick a low-pressure moment — a drive, a walk — rather than a formal sit-down. Lead with what you have noticed and how you feel, not with an accusation: “I have noticed you seem withdrawn lately, and I am worried about you.” Then listen more than you talk. You are trying to understand, not to win. The first conversation rarely settles everything; its real job is to open the channel.

Denial is common and does not mean the conversation failed. You do not need a confession to keep paying attention or to seek advice. Stay calm, avoid turning it into a battle to be won, and let them know the door stays open. If the signs persist, a professional can help you assess the situation without relying on your teenager admitting anything — and can guide how you respond next.

Sooner than you might think. You do not need certainty, or a confession, to talk to a psychologist — a cluster of changes that worries you is reason enough. Professional help is especially important if the changes are severe or lasting, if daily life is slipping, or if there is any sign of self-harm. Early support genuinely improves outcomes, for substance use and for the depression or anxiety that often sits underneath.

Treat it as urgent. If your teenager shows signs of self-harm, or hints that they do not want to be alive, do not wait to be sure — reach out to a mental health professional or your doctor straight away, and stay close to them in the meantime. This is one situation where acting early, even on an uncertain worry, is always the right call.