Medical Cannabis for Attention Deficit Hyperactivity Disorder (ADHD)

Summary

There is some promising evidence that medical cannabis can help manage some of the signs and symptoms of ADHD, including short attention spans, constant fidgeting, excessive physical movement, and anxiety. Medical cannabis may also help reduce the intake of some ADHD medications.

Data Overview

  • Total Studies = 12
  • Positive Studies = 10
  • Inconclusive Studies = 2
  • Negative Studies = 0
  • 7 Meta-Analyses (5 positive, 2 inconclusive); 3 Animal Studies (all positive); 1 Double-Blind Human Trial (positive); 1 Human Trial (positive)
  • 2 studies include CBD (both positive); 2 studies include THC (both positive); 1 study includes CBN (positive); 1 study includes a THC:CBD 1:1 ratio (positive)
  • Possible Overall Efficacy: Moderate

Key Takeaways

Pros

  • Many ADHD medications are stimulants, which can have side effects like insomnia, nausea, vomiting, headaches, numbness, tingling, and heart palpitations. Cannabinoids like THC, CBD, and CBN may control hyperactivity and impulsivity with fewer side effects.
  • Medical cannabis may help alleviate ADHD symptoms and reduce ADHD medication intake by acting on dopamine and norepinephrine receptors in a non-direct way and enhancing serotonin receptor activity, which has the side effect of lowering reward-seeking behavior.
  • Terpenes like pinene, limonene, and beta-caryophyllene can help relieve stress.
  • Myrcene-rich cannabis may be utilized for its sedative effects, which can help relieve anxiety and insomnia caused by ADHD and/or stimulant use.
  • Limonene may also help reduce cravings for stimulants like methamphetamine.
  • THC stimulates appetite, which can be diminished in those using stimulants.
  • There is some qualitative evidence for the efficacy of cannabis for ADHD.
  • Non-intoxicating cannabinoids like CBD may be ideal for children, as those compounds have far fewer side effects than prescription medications.

Cons

  • Adults with ADHD may respond better to medical cannabis treatment than children with ADHD. This could be due to THC sensitivity, though children may fare better with CBD.
  • Some people with ADHD/ADD may be sensitive to THC due to a compromised hypothalamic-pituitary-adrenal axis (HPA axis), which controls reactions to stress. Too much THC may cause anxiety and further compromise the HPA axis. On the other hand, cannabinoids may help re-regulate the HPA axis in those with ADHD. Appropriate dosing may be key to getting the best out of medical cannabis.
  • Reward-seeking behavior in ADHD may lead to cannabis use disorder (CUD).
  • High doses of THC may make keeping focus difficult for some people.
  • Dry mouth and anxiety can be exacerbated by the concurrent use of stimulant medications, especially if high doses of THC are used.

Introduction: What is ADHD?

Attention deficit hyperactivity disorder (ADHD), previously known as attention deficit disorder (ADD) and the hyperkinetic reaction of childhood, is a neurodevelopmental disorder characterized by hyperactivity, impulsivity, emotional dysregulation, and an inability to keep attention. Although it is most often associated with children, many adults live with ADHD.

Depending on the criteria used, ADHD affects about 5%-7% of children (DSM-IV) or 1%-2% (ICD-10), and these rates seem stable across countries. According to a national survey of parents in the U.S., the prevalence rate of ADHD is 6 million (9.8%) children aged 3-17 using data from 2016-2019. Boys are more likely to be diagnosed with ADHD than girls.

There is no known cause of ADHD, but it is associated with neurofibromatosis and mutations in the NF1 gene. ADHD runs in families and has a heritability rate of around 74%. Toxins, infections during pregnancy, and brain damage are other risk factors. Mutations in the NF1 gene are also associated with autism. Tourette syndrome (TS) is also associated with ADHD, with up to 50% of children diagnosed with ADHD having a tic disorder.

Those with ADHD are also more prone to substance misuse disorder. Part of this may be due to a sub-performance of dopamine and norepinephrine receptors, leading to improperly-used dopamine in the brain. This causes the brain to constantly seek reward, jumping from unfinished task to unfinished task to get a dopamine hit. This pattern of behavior may also increase the likelihood of drug addiction.

Non-drug interventions include keeping to a daily schedule, regular exercise, reducing intake of processed foods and sugars, and various modes of therapy such as talking therapy. Stimulant medications such as methylphenidate (Ritalin) and dextroamphetamine (Adderall) are often prescribed. Non-stimulant prescription medications include anti-anxiety medications like buspirone, a 5-HT1A agonist. Some may also utilize herbal medications like chamomile, ginseng, and ginkgo Biloba.

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Why Might Cannabis Help Manage ADHD?

You can read more on why medical cannabis can help manage ADHD here. There are two possible explanations, which may both be true. ADHD is associated with mutations in the NF1 gene, which encodes neurofibromin, acts as a tumor suppressant, and helps with functions such as learning, memory, and concentration. NF1 mutations may cause inflammation, leading to stress and endocannabinoid system dysregulation. Phytocannabinoids can help re-regulate the ECS and reduce inflammation, helping manage ADHD and some symptoms.

Two, using THC may help boost dopamine levels in the brain in a much safer way and has far fewer side effects than stimulant-based medications like dextroamphetamine (Adderall). Cannabis also contains several anxiolytic (anti-anxiety), stress-busting, stimulating terpenes like limonene and pinene and sedative terpenes like myrcene and humulene. Using the suitable terpenes and cannabinoids in the right combination at the right time of day can help keep focus during the day and provide relaxation and sedation at night.

Conclusion

There is compelling evidence that medical cannabis can be used to help manage some of the symptoms of ADHD, especially in adults. The few human trials that have been carried out have shown positive results, and anecdotal evidence backs up these promising results. The main area medical cannabis may help reduce stimulant and antidepressant medications. However, clinical trials are few and far between, and it is also worth noting that ADHD is not yet a qualifying condition for medical cannabis in any U.S. state. This can make it very difficult to determine how beneficial medical cannabis is for people with ADHD. However, this looks set to change as acceptance of medical cannabis grows.