
Are You Concerned About Cannabis Addiction?
Cannabis is the most commonly reported drug of concern among young people in Ireland today. Over 45,000 adolescents have been referred to addiction services because of cannabis use, making it the leading cause of drug-related referrals for this age group. While often seen as a “soft drug,” cannabis can be addictive and have serious effects on mental health, motivation, and overall well-being. On this page, we look at how cannabis use turns into cannabis addiction, why teens may be especially at risk, and what help is available for those struggling.1
At Smarmore Castle, we understand the unique challenges of overcoming cannabis addiction. Our experienced team provides compassionate, evidence-based cannabis addiction treatment and care in a safe and supportive environment to help set you or your loved one on the path to recovery.

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What Is Cannabis Addiction?
Cannabis addiction, also known as cannabis use disorder or marijuana addiction, involves a physical or psychological craving and cannabis dependence, a reliance on cannabis products such as weed, hash, or synthetic cannabinoids. While many believe cannabis is harmless or recreational, its long-term use can lead to an increased risk of dependency and drug addiction, impacting a person’s mental health, motivation, and ability to function well. It can also be difficult to stop using cannabis without seeking professional medical support.
The cannabis plant contains a psychoactive chemical called tetrahydrocannabinol (THC), which targets areas in the brain that influence pleasure as well as memory and coordination. While smoking a joint might make you feel happy and chilled, it can also impact your brain and affect your ability to remember or leave you unsteady on your feet.2,3
Chronic, everyday use of cannabis products (especially those that include THC) is associated with developing cannabis use disorder. Cannabis addiction is referenced in the DSM-5 and has been explored in other sources, such as DSM-5 Criteria for Substance Use Disorders. According to the analysis of multiple studies conducted on cannabis use, around 22% of people who consume cannabis suffer from cannabis use disorder or addiction.3-6
What Is the Difference Between Weed, Hash, and Synthetic Cannabinoids?
Cannabis (weed) is the dried leaves, flowers, stems, and seeds of the cannabis sativa plant. Hash is a concentrated form made from the resin of the plant. Synthetic cannabinoids are man-made substances that mimic the effects of THC but can be significantly more dangerous, often leading to synthetic cannabis addiction.3
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Signs and Symptoms of Cannabis Addiction
Whilst the effects of cannabis are considered by many people to be less intense than other drugs such as opioids, consuming cannabis regularly and heavily can still lead to a person developing physical cannabis withdrawal symptoms such as headaches, nausea, and insomnia, as well as mental health issues and other psychological effects. Long term cannabis use and the high potency cannabis consumption can also lead to other, more worrying side effects, such as cannabis induced psychosis. Recognising cannabis withdrawal symptoms, and the physical health issues and psychological signs of cannabis addiction is the first step towards recovery.
Physical Symptoms and Signs of Cannabis Use 7,8:
- Bloodshot eyes
- Dry mouth
- Feeling hungry
- Neglecting hygiene
- Headache
- Stomach ache
- Inability to sleep
- Feeling dizzy
- Sweating
- Having the chills
- Weight loss
- Cravings
Psychological Signs and Symptoms of Cannabis Abuse 7,8:
Cannabis can cause both physical and mental health issues. The signs of psychological dependence include strong cravings, severe anxiety when not using cannabis (or as the drug wears off), and a need to consume it to manage symptoms of stress and anxiety.
- Memory problems
- Mood swings and irritability
- Anxiety or paranoia
- Loss of motivation
- Depression
- Irritability
- Nervousness
- Aggression
- Inability to concentrate
- Psychosis (paranoia, hallucinations, altered state of mind)
Cannabis Use in Ireland
Cannabis remains the most widely used illicit drug in Ireland, and its impact on mental health is significant. According to the Health Ireland Survey, one in five people (20%) reported lifetime use of cannabis. It was also the most common additional drug in 2023, reported by cases with polydrug use (those using more than one drug), and has been linked to mental health conditions.8,9
Synthetic cannabis addiction is an emerging threat, particularly among younger cannabis users in Ireland. These substances are often more potent and dangerous than natural cannabis, leading to severe health risks and unpredictable side effects.1
How Cannabis Addiction Develops
Addiction can develop gradually through patterns of social use, self-medication for anxiety or depression, and regular exposure to high-THC strains. Over time, the brain adapts to the constant presence of THC, making day-to-day life feel more difficult without it.
The younger you are when you start using cannabis, the higher your risk of experiencing harms, including developing cannabis dependency.10
How Does Cannabis Affect the Brain?
Research shows that prolonged cannabis use affects brain chemistry, particularly in areas responsible for memory, motivation, and emotional regulation. Research has found that chronic cannabis use may affect brain regions related to memory and reward, particularly in younger users.
THC, the main psychoactive component in cannabis, alters brain chemistry, negatively affecting memory, decision-making, and emotional regulation. High-THC strains, now common in Ireland, pose additional risk factors that have negative consequences, increasing the likelihood of addiction and mental health problems such as anxiety, depression, and psychosis.2,5,10
Cannabis use can impact brain development and function in the following ways:
- Memory and cognitive function are impacted, especially in young users.
- The risk of anxiety disorders, depression, and psychosis is increased.
- The brain’s reward system is affected, making it harder to feel pleasure without the drug.
How do I get help for cannabis addiction?
You have already taken a brave first step towards getting help, and you are not alone. The next step on the path to recovery is to begin cannabis treatment within an addiction treatment programme that can provide support, help you detox safely and manage cannabis withdrawal, and where you can learn the tools and strategies you need via therapeutic interventions like cognitive behavioural therapy (CBT) to help manage your cravings and help you find lasting recovery through aftercare and relapse prevention programmes.
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If you or a loved one is struggling with cannabis addiction or drug addiction, we’re here to talk. Reach out today to learn more about how we can help. Contact Smarmore Castle today for confidential advice and support.

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Free Resources for Ongoing Support for Cannabis Misuse
There are community support groups that may be local to you that can provide support for you and your loved ones, and where you can build connections and learn from one another’s experiences with cannabis addiction. You can find local drug addiction services via HSE as well as Narcotics Anonymous (NA), which can provide a continuation of support based on the 12 steps.
Frequently Asked Questions About Cannabis Addiction
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Is cannabis physically addictive?
Yes, while it primarily causes psychological dependence, heavy use can lead to physical cannabis withdrawal symptoms. [7]
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What are typical cannabis withdrawal symptoms?
There are many symptoms of withdrawal from cannabis that affect physical and mental health. Some are physical, such as changes in appetite, flu-like symptoms, and stomach pain. Withdrawal can also cause irritability, insomnia, loss of appetite, anxiety, and restlessness. [7]
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How long does rehab from cannabis take?
The length of cannabis rehab varies from person to person but typically involves several weeks of support. At Smarmore Castle, our drug detox usually lasts between 7 and 14 days, however, the process will take as long as the individual needs to safely detox and withdraw from cannabis. Once detox is complete, addiction therapy begins.
A person’s recovery journey can be personal and take as long as the individual needs. However, residential rehab at Smarmore Castle will typically last between 4 and 12 weeks depending on the severity of the addiction and any mental health conditions.
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Is synthetic cannabis more dangerous than regular cannabis?
Yes, synthetic cannabis addiction poses higher health risks due to its unpredictable potency and severe side effects. Synthetic cannabinoids produce different effects from the effects of THC (delta-9 tetrahydrocannabinol), the active ingredient in cannabis. The effects can often be more dangerous and unpredictable. [11]
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What should I do if a loved one is addicted to cannabis?
It can be difficult if a loved one is struggling with cannabis use disorder and mental health. Often, it can be distressing, and even, at times, financially difficult. Offering non-judgmental support is key. Encourage them to seek professional help.
You are not alone. Help is available to you and your loved one. You may also require support. Learn how we support families with family therapy at Smarmore Castle.
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How can I prevent cannabis addiction?
Education, setting healthy boundaries, and developing strong coping skills are key to prevention. Whilst some people do not develop marijuana addiction or cannabis use disorder, it can happen. Being aware of the signs and symptoms will help you to be more aware of the effects. At Smarmore Castle, we provide treatment options to help you begin recovery, however, it may also be necessary to seek advice first from your GP.
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What does cannabis addiction look like?
It often involves daily use, withdrawal symptoms when not using, and neglect of personal responsibilities and well-being. Cannabis users may have urges to use cannabis may lead them to sacrifice important commitments such as work or school to acquire and use marijuana. [12]
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References
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- College of Psychiatrists of Ireland. Cannabis is now the main drug driving referral to adolescent addiction services. [Accessed May 2025].
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- Lafaye G, (2017), Cannabis, Cannabinoids and Health, Dialogues Clin Neurosci: 19 (3), 309-316.
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- National Institute on Drug Abuse (NIDA). Cannabis (Marijuana). [Accessed May 2025].
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- Leung J, Chan GCK, Hides L, Hall WD. What is the prevalence and risk of cannabis use disorders among people who use cannabis? a systematic review and meta-analysis. Addict Behav. 2020;109:106479. doi:10.1016/j.addbeh.2020.106479
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- Zehra A, Burns J, Liu CK, Manza P, Wiers CE, Volkow ND, Wang GJ. Cannabis Addiction and the Brain: A Review. J Neuroimmune Pharmacol. 2018 Dec;13(4):438-452. doi: 10.1007/s11481-018-9782-9. Epub 2018 Mar 19. PMID: 29556883; PMCID: PMC6223748.
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- Hartney, E.BSc, MSc, MA, PhD, and Umhau, J.C. MD, MPH, CPE. What is Cannabis Use Disorder?[Accessed May 2025].
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- Hartney, E.BSc, MSc, MA, PhD, and Gans, S., MD. What Do Marijuana Withdrawal Symptoms Feel Like? [Accessed May 2025].
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- Health Research Board. Factsheet: Cannabis – the Irish situation. [Internet]. Ireland: April 2025. [Accessed May 2025].
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- Healthy Ireland. Healthy Ireland survey 2023: summary report [Internet]. Government of Ireland. [Accessed May 2025].
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- Drugs.ie. Drug and Alcohol Information and Support. Cannabis. [Accessed May 2025].
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- Alcohol and Drug Foundation. Synthetic Cannabinoids. [Accessed May 2025].
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- Buddy, T., and Gans, S. MD. 5 Signs of Marijuana (Weed) Addiction. [Accessed May 2025].
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