Yes, cannabis can be addictive. The US National Institute on Drug Abuse (NIDA) estimates that 22% to 30% of people who use cannabis develop cannabis use disorder, the medical name for being unable to stop despite the harm it causes. The signs are using more and more often, failing to cut down, and feeling irritable, anxious and unable to sleep without it. It responds to treatment, mainly talking therapies, and families can make the first call.
In Malaysia, cannabis (ganja, also called weed) is a dangerous drug under the Dangerous Drugs Act 1952, so worry about the law often sits on top of worry about health. This guide covers both.
How dependence develops
Most people who try cannabis do not become dependent. The risk rises with how often and how strong. NIDA says regular, heavy use is the strongest predictor of cannabis use disorder, and that starting young makes it more likely later in life.
The change is usually gradual. Weekend use becomes evening use, then daily use. The same amount starts to do less, so the person needs more (doctors call this tolerance). Before long they feel restless, irritable or unable to sleep without it, and they are using mainly to feel normal. By then, stopping is harder than they expected, even when they want to.
Strength matters too. NIDA reports that the average THC content of illegal cannabis seized in the United States rose from about 4% in 1995 to about 16% in 2022. THC is the chemical that produces the high. Stronger cannabis means more exposure with every joint.
Signs to look for
NIDA lists the features doctors look for in cannabis use disorder. In everyday terms:
- Needing more cannabis to get the same effect.
- Strong urges to use, and repeated promises to cut down that do not last.
- Giving up hobbies, sport, time with family or work to use.
- Irritability, anger or poor sleep on days without it.
- In young people, slipping at school or college. NIDA links regular heavy use in adolescence to weaker memory, slower thinking and poorer grades.
- Anxiety, suspicion or paranoia that was not there before.
One sign on its own proves little. Several together, over months, are worth a conversation with a professional.
What withdrawal feels like
Cannabis withdrawal is unpleasant, and it passes. According to Cleveland Clinic, symptoms usually start within 24 to 48 hours of stopping after heavy, long-term use, are worst by about day three, and ease over up to two weeks. Some, especially poor sleep, can last three weeks or longer in heavy users.
The common symptoms, as listed by NIDA and Cleveland Clinic, are:
- irritability, anger or aggression
- anxiety and restlessness
- poor sleep and vivid, disturbing dreams
- loss of appetite and some weight loss
- low mood
Cleveland Clinic notes that withdrawal tends to be harder for daily users, people using high-potency products, people who also smoke tobacco, and people with depression, anxiety or post-traumatic stress. This irritable, sleepless stretch is often when an attempt to stop at home breaks down, and it is easier to get through with support.
Cannabis, anxiety and psychosis
Cannabis can make people anxious, panicky and paranoid. FRANK, the UK government's drug advice service, says it can bring hours or even days of anxiety, paranoia and hallucinations.
The more serious risk is psychosis, which means losing touch with reality: hearing voices, holding fixed false beliefs or becoming very suspicious. A large European study published in The Lancet Psychiatry in 2019 found that people who used high-potency cannabis every day had nearly five times the odds of a psychotic disorder compared with people who had never used it. FRANK adds that the risk of illnesses such as schizophrenia is higher when someone starts in their teenage years or has a family history of mental illness, and that cannabis can trigger relapse in people who already have a psychotic illness.
If someone is hearing voices, is very paranoid, talks about harming themselves or others, or has collapsed, call 999. Psychosis needs medical and psychiatric assessment. When cannabis use comes with depression, anxiety or psychosis, treating both together is called dual diagnosis treatment.
Ganja and Malaysian law
Cannabis is a dangerous drug under the Dangerous Drugs Act 1952. In the Ministry of Health reprint of the Act:
- Using cannabis (section 15(1)(a)) carries a fine of up to RM5,000 or up to 2 years in prison.
- Possessing cannabis (section 6) carries a fine of up to RM20,000, up to 5 years in prison, or both. From 20 g the heavier penalties in section 39A apply, including whipping.
- Having 200 g or more is presumed to be trafficking (section 37(da)).
- Growing cannabis (section 6B) carries life imprisonment and at least six strokes.
Medical cannabis is a narrow, regulated route. In March 2025 the Health Minister said that anyone with enough scientific evidence can apply to register a cannabis-based medicine with the Drug Control Authority. At that time no such product was registered. Sativex, a cannabis-based mouth spray, was registered in 2014 and withdrawn in 2017 at the company's request. We have found no report of a product being registered since then, as at October 2026. Cannabis or THC products bought online or from friends are not registered medicines, whatever the label says.
AADK, the National Anti-Drugs Agency, recorded 7,121 cannabis cases in 2024, up 63.4% from 4,358 in 2023. Our guide to drug laws in Malaysia sets out the penalties in full and explains the 2025 treatment law for people who come forward voluntarily.
Treatment that works
There is no approved medication for cannabis use disorder, so treatment is psychological. NIDA names three approaches with good evidence:
- Cognitive behavioural therapy (CBT) helps the person spot the situations, moods and thoughts that lead to using, and practise other ways to handle them.
- Motivational interviewing, also called motivational enhancement therapy, is a conversation style that helps a person weigh up their own reasons to change, without lectures. It suits people who are unsure they have a problem.
- Contingency management gives small, immediate rewards for verified time without the drug, such as clean urine tests.
If your son or daughter is using weed
Start calmly and when they are sober. Ask what cannabis does for them: helps them sleep, calms anxiety, fits in with friends. The answer usually points to what treatment needs to address. Our guide on how to talk to someone about getting help covers the first conversation.
Common questions
Is weed addictive?
Yes, for a sizeable minority. NIDA estimates that 22% to 30% of people who use cannabis have cannabis use disorder. Daily use, strong products and starting young all raise the risk.
How long do weed withdrawal symptoms last?
They usually begin within one to two days of stopping, peak around day three and ease within about two weeks. Poor sleep and vivid dreams can last longer in heavy users.
Can cannabis cause psychosis?
It can, especially with daily use of strong cannabis. A 2019 European study found daily high-potency use linked to nearly five times the odds of a psychotic disorder. The risk is higher for people who start young or have a family history of mental illness.
Is medical cannabis legal in Malaysia?
Only through registration with the Drug Control Authority, and as of March 2025 no cannabis-based medicine was registered. Cannabis bought outside that route remains a dangerous drug under the Dangerous Drugs Act 1952.
My son is addicted to weed. What do I do?
Talk to him calmly, find out what he uses it for, and get professional advice early. You can speak to a treatment service before he agrees to anything. If he is paranoid, hearing voices or has collapsed, call 999.
How Salus can help
Salus runs a private, confidential, voluntary 90-day residential programme for adults aged 18 and over in Cyberjaya, Selangor. Every guest has a medical, psychiatric and psychological assessment on arrival, withdrawal is managed alongside medical care, and a Salus Clinician plans daily life with each person. The cost is RM7,000 per month, all-inclusive: a private room, meals, 24-hour care and medical oversight, individual and group therapy, family sessions and an aftercare plan. Our drug rehabilitation centre page explains the 90 days.
Families can call first, before the person agrees to anything. Call or WhatsApp Salus for a confidential conversation about what you are seeing.
This article is general information, not medical advice.
