Is cannabis addictive? What science says about hashish, the brain and mental health

Is cannabis addictive? The short answer first

Yes. Cannabis is addictive, hashish included; this is the conclusion of the major health bodies, not an opinion. The World Health Organization (WHO) says that developing a cannabis dependence syndrome, marked by a loss of control over use, is likely in people who use cannabis regularly over a long period. The U.S. Centers for Disease Control and Prevention (CDC) estimates, on its page updated in 2024, that about 3 in 10 people who use cannabis have cannabis use disorder and that this share is rising, while the U.S. National Institute on Drug Abuse (NIDA, 2024) puts the estimate at 22% to 30%.

To be fair, not everyone who tries hashish becomes dependent. But a significant share do, and there is no way to know in advance which group you, or your child, will fall into. Nor does being common make a substance safe: the WHO notes that no illicit drug in the world is grown, smuggled or used more widely than cannabis.

It is the same plant under many local names: hashish and bango in Egypt, zatla, kif and majoun in Morocco, Algeria and Tunisia, and bango and shashamandi in Sudan. A different name changes nothing about how the substance works inside the brain.

Hashish vs. marijuana (bango): the difference, and why today's products have changed

Both come from the same cannabis plant; the difference is the part that is used. Bango (marijuana) is the dried leaves, flowers, stems and seeds of the plant, while hashish is a substance extracted from the flowering tops of female plants, and the MedlinePlus medical encyclopedia notes that it contains the highest amount of the active ingredient tetrahydrocannabinol (THC). Both contain this substance and both can cause dependence; the difference is one of concentration, not of kind.

More important than that difference: the product itself has changed. MedlinePlus notes that the active-ingredient content of cannabis products has risen over time, and that stronger products raise the risk of addiction. NIDA adds that higher concentrations of this substance have been linked to a greater likelihood that use progresses to cannabis use disorder. Put simply: what a father or uncle experienced many years ago is no measure of what his son is exposed to today.

Cannabis use disorder: how to tell use from dependence

Dependence is not a number of uses but a repeating pattern that causes clear distress or harm in a person's life. NIDA notes that a medical diagnosis of cannabis use disorder is based on having two or more specific signs within 12 months, and only a doctor can make the diagnosis. Among the most prominent signs:

• Repeated attempts to stop or cut down that fail every time.
• Needing more to get the same effect that came at the start (tolerance).
• A lot of time lost thinking about the substance, getting it or recovering from its effects.
• Carrying on despite clear problems at school, at work or at home.
• Giving up hobbies, relationships and activities that used to matter, as life shrinks around the next time.
• Tension, irritability and distress that appear on stopping and settle as soon as use resumes.

Withdrawal symptoms are among the clearest signs that the body has become used to the substance. NIDA (2024) notes that they can include anger, irritability, aggression, nervousness, anxiety, restlessness, loss of appetite, weight loss, low mood, insomnia, strange and disturbing dreams, headaches, sweating, stomach pain and shakiness, and that one study estimated that 12.1% of people who use cannabis frequently go through cannabis withdrawal.

Effects of hashish on the brain: memory, focus and driving

The CDC explains that cannabis acts directly on the brain areas that handle memory and learning, attention, decision-making, coordination, emotions and how quickly a person reacts. NIDA links frequent or heavy use to problems with learning, memory, attention, mental processing speed and language. The WHO adds that recalling learned information is impaired when both learning and recall happen under the influence of cannabis.

The heaviest impact falls on a brain that is still developing. NIDA links regular, heavy use in adolescence to negative effects on working memory, processing speed, verbal memory and school performance, and even to poorer outcomes in education, employment and income in early adulthood. This is what families describe in their own words: "My son has lost interest in everything."

Driving affects other people too. The WHO notes that performance on complex tasks may remain affected for up to 24 hours after use, and NIDA notes that cannabis is the drug most often found in the blood of drivers involved in road crashes, including fatal ones. It adds that several analyses have found a higher crash risk after use, although one study by the U.S. National Highway Traffic Safety Administration found no significant increase attributable to cannabis. The evidence is not fully settled, but the direction is clear enough: no driving under the influence.

Cannabis and mental health: anxiety, mood, sleep and psychosis

Many people start using hashish to escape anxiety, insomnia or a heavy mood, then discover the problem has grown. The CDC notes that cannabis use has been linked to social anxiety, depression and schizophrenia, while cautioning that scientists do not yet fully understand the nature of these relationships. NIDA points to a higher risk of depression in people who use cannabis as teenagers, and to research linking it to suicidal thoughts and behaviors in adolescents.

Sleep can be deceptive too: using may seem to help at first, but insomnia and disturbing dreams are among the best-known withdrawal symptoms, so the "sleep aid" ends up causing sleepless nights.

Cannabis, sex, marriage and fertility: what the evidence does and does not say

The common belief that hashish "makes sex last longer" or improves sexual performance is not supported by the evidence, which points the other way. A systematic review published in the journal Cureus in 2021 states that the data suggest erectile dysfunction is about twice as common in people who use cannabis as in those who do not, and that any early increase in desire appears to be short-lived. These observational findings do not on their own prove cannabis is the cause, but they do not support the idea that it "helps."

On fertility, the same review concluded that cannabis appears to harm sperm parameters (count, concentration, motility, shape and viability), which may affect male fertility. But it added important caveats: not every study it included found harm, the hormone findings were inconclusive, and the available studies are observational and involve small groups in which other factors may play a part, so larger research is needed.

At home, what wears down a marriage most is not the substance itself but everything around it: withdrawing from communication, irritability that flares before the next time, money that disappears, repeated promises to stop that are never kept, and trust that slowly erodes. These are not personal disagreements to be settled by arguing, but symptoms of a treatable condition.

Who is most at risk of cannabis addiction?

The risk is not the same for everyone. The groups most at risk are:

• Teenagers and young people: the brain is still developing, and starting young raises the risk of cannabis use disorder later on, as the CDC notes.
• People who use often or daily: MedlinePlus notes that the chance of addiction is higher in people who use every day or who started as teenagers.
• People who use stronger products: as explained above, higher concentrations raise the risk of cannabis use disorder.
• People with a family history of drug use: NIDA notes that this can also play a role in cannabis use disorder. A family history of psychosis or schizophrenia carries a different risk, covered in the mental health section above.
• People who turn to hashish to calm anxiety, sadness, insomnia or life stress: it postpones treating the original problem, and since anxiety and insomnia are also withdrawal symptoms, the cycle keeps turning.

When should you seek help?

Don't wait for a rock bottom like the ones in films. Seek specialist help if you notice any of the following:

• You have tried to stop on your own more than once and it did not last.
• Clear withdrawal symptoms appeared when you stopped and pushed you back to using.
• Use has started to affect school, work, money or your relationship with your family.
• Use comes with severe anxiety, persistent low mood or long-lasting insomnia.
• The person using is a teenager, or has a family history of mental illness.
• The amount has gone up, or the person has started using alone or in the morning.

How is cannabis dependence treated?

The good news is that this condition has a clear treatment path, and recovery is possible. It starts with a medical assessment that builds the full picture: how long use has gone on, whether other substances are involved, and whether depression, anxiety or psychosis also needs treatment.

1. Initial assessment: telling cannabis use disorder apart from a separate mental health condition with similar symptoms, because the treatment plan is different.
2. Managing the withdrawal period: medical follow-up that eases insomnia, tension and loss of appetite in the first days; if alcohol, sedatives, pregabalin or opioids such as tramadol are involved too, it must happen under medical supervision, never at home alone.
3. Psychological therapy, the foundation of treatment: NIDA notes that behavioral interventions such as cognitive behavioral therapy, motivational enhancement therapy and incentive-based therapy (contingency management) can be effective in treating cannabis use disorder.
4. Treating what comes with it: depression, anxiety, insomnia or attention problems (ADHD), as decided by the doctor alone.
5. Rehabilitation and relapse prevention: building a day without the substance, skills for handling cravings and stress, and follow-up after the intensive phase ends.

Note that there is still no medication approved by the U.S. Food and Drug Administration (FDA) to treat cannabis use disorder itself or its withdrawal, as NIDA notes; what a doctor sometimes prescribes is for the insomnia, anxiety or depression that comes with it, and no medication should be started or stopped on your own.

At Oxygen Center in Damanhour, assessment and treatment are confidential and depend on each person's needs: inpatient care through our addiction treatment program followed by psychological and behavioral rehabilitation, for males aged 15 and over (under 18 with a guardian's consent), or outpatient doctor appointments and therapy sessions, which are open to men and women. For those in Egypt who prefer a government option, the Fund for Drug Control and Treatment of Addiction runs a hotline on 16023 that offers confidential treatment through partner centers. Whether this is for you or someone you love, the next step is simple: get in touch on +20 101 687 0711 and ask. Asking commits you to nothing; only waiting has a cost.