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  • Drew Herb Lesser

Adult ADHD: The power of Medical Cannabis and CBD

Updated: Dec 20, 2023

Adult attention-deficit/hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders affecting around 1 in 20 Australians has ADHD. More than 3 in four children diagnosed with ADHD continue to experience the symptoms into adulthood. ADHD affects the brain's executive functioning, the ability to self regulate and control thoughts, words, actions and emotions. ADHD is characterised as a disorder with symptoms ranging from difficulty paying attention, hyperactivity and impulsive behavior. Adult ADHD can lead to alcohol abuse, unstable relationships, poor school or work performance, low self-esteem, and interference with daily functioning. This can range from mild to severe. Often adults with ADHD are unaware they have it, they just experience life’s tasks as more challenging. Adults with ADHD may find it difficult to focus, prioritise and organise, leading to forgotten social plans and meetings and missed deadlines at work or school. The inability for impulse control ranges from general impatience to mood swings and/or outbursts of anger.

How is it possible that a diagnosis of ADHD could have been missed?

Because the symptoms of ADHD are similar to anxiety and various mood disorders, and the fact that research indicates, more often than not, individuals with ADHD have a co-morbid mental health condition such as anxiety or depression. It can oftentimes be missed as a diagnosis

What triggered the interest in Medical Cannabis as a treatment for ADHD?

The traditional treatment for ADHD, at all ages, is medication and the most widely prescribed treatment for ADHD are stimulants such as D-amphetamine (Dexedrine) and methylphenidate (Ritalin). The heavy interest in alternative plant based medicines for the treatment of ADHD has been spearheaded by the concerning short and long-term side effects of these medications. The marijuana plant has some of the most potent compounds to fight disease and inflammation: terpenes, and cannabinoids. The natural properties of the cannabis sativa and cannabis ruderalis plants are remarkably comparable to amphetamine treatments. Since CBD has no psychoactive effects, it is a perfect treatment for anxiety.

What is CBD?

Cannabidiol oil, CBD oil, is a product of the marijuana plant. It is not THC

(tetrahydrocannabinol), the euphoric compound in cannabis that creates the "high." CBD oil is refined to remove the THC, making it suitable for certain medical applications.

There are numerous anecdotal reports on the treatment of ADHD with CBD oil, whilst there is limited research on this treatment protocol for individuals who experience anxiety and/or epilepsy, CBD oil has been shown to significantly relieve symptoms.

So what does the research say about CBD and Medical Cannabis?

Study 1: In a randomised controlled trial, cannabinoids - CBD were used to treat ADHD. The participants were evaluated for symptom levels and IQ performance, registering an insignificant improvement on cognitive function and symptom reduction, however what was discovered in the recorded data was that impulsivity and hyperactivity, two KEY factors, which evidence a diagnosis of ADHD, both experienced a reduction.

Study 2: In a second study looking at cannabinoids in attention-deficit/hyperactivity disorder, it was discovered that cannabinoids could significantly improve symptoms in ADHD.

Despite the fact that cannabinoid-dopamine interactions have provided conflicting evidence from human and animal research trials, we do know that THC causes increased dopamine release and neuron activity. However the examination of the long-term and developmental dopaminergic effects of the THC in cannabis need to be researched further.

Study 3: A qualitative analysis of online forum discussions on the effects of cannabis on ADHD study looked at discussion threads to understand the perception of individuals with ADHD in relation to cannabis. The study reported that 25% of people believe that cannabis had a positive role to play in ADHD symptom management.

CBD advocates claim greater efficacy with fewer, if any, side effects than other ADHD medication, on the basis that it’s plant based medicine. The cannabis plants have been grown to maximise the different terpenes, for example, industrial hemp is grown for its fibers, while another strain for medicinal purposes is grown for its seeds. Industrial hemp cannot produce sufficient amounts of cannabidiol oil and it is often extracted from phytocannabinoid-rich hemp, which has had THC components removed through breeding. The plant looks very similar to a cannabis plant and is a variant of the original cannabis plant.

CBD is believed to work by several mechanisms:

  1. The Anticholinergic effect of CBD counteracts excessive accumulation of acetylcholine at the neuromuscular junctions and synapses causing symptoms of toxicity such as cramps, increased salivation, muscular weakness, paralysis, muscular fasciculation, diarrhoea, and blurry vision and reactions that contribute to pain and depression and symptoms such as sweating, hypersalivation, stomach upset, and racing heartbeat.

  2. The Anti-inflammatory effect of CBD has been shown to help with depression, ADHD, and even autism spectrum disorders. In ADHD, reduced inflammation can stabilise the nervous system, reducing symptoms which can aggravate ADHD.

  3. Analgesic effects of CBD engage the body’s endocannabinoid system supporting a protocol of pain management. CBD binds to receptors providing anti-anxiety and anti-convulsant responses.

  4. The Dopaminergic effect of CBD supports the production of more dopamine, a neurotransmitter that we know is impaired in some individuals with ADHD, and responds to stimulant medication. A study evaluating the effects of Δ9-tetrahydrocannabinol on the dopamine system, indicated that THC boosted short term dopamine levels.

What about research specific to cannabis and kids with ADHD?

There is currently no research that looks at cannabis as an intervention for children with ADHD, while there is anecdotal evidence cannabis assists children with ADHD, more studies need to be conducted within this domain. The impact of cannabis use on the executive functioning of young adults with a diagnosis of ADHD is definitely a concern and the researchers have found that individuals who use cannabis, that is Full Spectrum CBD with THC (the psychoactive component of the cannabis plant) before age sixteen, were at risk for developmental neuropsychological complications. For this reason, dosing for pediatric purposes is typically made with a low THC strain, having THC levels which are undetectable.

Is medical cannabis prescribed for ADHD in Australia?

Medical cannabis has been prescribed and approved by the TGA for people with ADHD. For patients under the age of 16, where the medication will contain THC, you’ll likely need endorsement from a specialist to get TGA approval.

Take Aways

Cannabis is being used all over the world as a treatment for ADHD. Quite often this is self-medication or cannabis use without a prescription. The multiple benefits of medical cannabis, including the reduction in symptoms associated with ADHD and anti-inflammatory effects on the body, position cannabis as a valuable medicine in the treatment of a variety of chronic illnesses and diseases. There are known cases of medicinal cannabis being approved for ADHD treatment in Australia. When applying for medicinal cannabis for a child with ADHD, you may need to provide a higher standard of medical evidence or endorsement from a specialist.

If you believe cannabis may be the right treatment for you please do your research and consult a healthcare professional, or contact our office to make an appointment to see a doctor who specialises in cannabis medicine. If any of the symptoms above continually diminish your capacity to enjoy your life fully, talk to your doctor about whether you might have ADHD.

Greenhouse Medical Clinic has strict sourcing guidelines and relies on peer-reviewed studies, academic research and medical association publications.



  • Barchel D, et al. (2019). Oral cannabidiol use in children with autism spectrum disorder to treat related symptoms and co-morbidities. DOI: 10.3389/fphar.2018.01521

  • Bidwell LC, et al. (2014). Childhood and current ADHD symptom dimensions are associated with more severe cannabis outcomes in college students. DOI: 10.1016/j.drugalcdep.2013.11.013

  • Bloomfield MA, Ashok AH, Volkow ND, Howes OD. The effects of Δ9-tetrahydrocannabinol on the dopamine system. Nature. 2016 Nov 17;539(7629):369-377. doi: 10.1038/nature20153. PMID: 27853201; PMCID: PMC5123717.

  • Cannabis and cannabinoids (PDQ) - patient version. (2019).

  • Cooper RE, Williams E, Seegobin S, Tye C, Kuntsi J, Asherson P. Cannabinoids in attention-deficit/hyperactivity disorder: A randomised-controlled trial. Eur Neuropsychopharmacol. 2017 Aug;27(8):795-808. doi: 10.1016/j.euroneuro.2017.05.005. Epub 2017 May 30. PMID: 28576350

  • Egan TE, et al. (2017). Substance use in undergraduate students with histories of attention-deficit/hyperactivity disorder (ADHD): The role of impulsivity. DOI: 10.1080/10826084.2017.1281309

  • Iffland K, et al. (2017). An update on safety and side effects of cannabidiol: A review of clinical data and relevant animal studies. (2017). DOI: 10.1089/can.2016.0034

  • Loflin M, et al. (2013). Subtypes of attention deficit-hyperactivity disorder (ADHD) and cannabis use. DOI: 10.3109/10826084.2013.841251

  • Mitchell JT, Sweitzer MM, Tunno AM, Kollins SH, McClernon FJ (2016) “I Use Weed for My ADHD”: A Qualitative Analysis of Online Forum Discussions on Cannabis Use and ADHD. PLOS ONE 11(5): e0156614.

  • Morse MC, et al. (2016). Disruptive behaviors and marijuana use: The role of depressive symptoms. DOI: 10.4137/SART.S31432

  • Schatz DB, et al. (2006). ADHD with comorbid anxiety: A review of the literature. DOI: 10.1177/1087054706286698

  • Silva N, et al. (2014). Searching for a neurobiological for self-medication theory in ADHD comorbid with substance use disorders: An in vivo study of dopamine transporters using (99m) Tc-TRODAT-1 SPECT. DOI: 10.1097/RLU.0b013e31829f9119

  • Treatment of ADHD. (2019).

  • Volkow ND. (2015). The biology and potential therapeutic effects of cannabidiol.


This information is not intended to be a substitute for professional medical advice and is provided for educational purposes only. It should not be relied on as health or personal advice. The author is NOT a Doctor. Always seek the guidance of your doctor or other qualified health professional with any questions you may have regarding your health or a medical condition.


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