Attention-deficit/hyperactivity disorder (ADHD) affects between 2% to 5% of the world’s population. It’s a growing concern in Australia, with ADHD diagnoses on the rise. However, the research into the effects medical cannabis has on ADHD isn’t conclusive.
Some studies show cautiously positive results in using medical cannabis to manage ADHD, while others find that cannabis use may pose unique risks for people with the condition. ADHD can be a debilitating condition, and often co-occurs with other mental health concerns such as anxiety. This can make ADHD hard to identify and diagnose, meaning education around the condition is vital.
What Is ADHD?
People with ADHD may display a range of different symptoms, but generally the condition involves difficulty concentrating on tasks a person doesn’t find stimulating, impulsive behaviour and excessive activity. People with ADHD often have impaired executive function, which is a cognitive process that allows us to plan, focus our attention, remember things and multitask.
There are several types of ADHD, but the three main types are:
- Impulsive/hyperactive ADHD – where someone is impulsive and hyperactive but not excessively inattentive or distractible.
- Inattentive/distractible ADHD – a type of ADHD characterised by difficulty paying attention and getting distracted easily, but without severe impulsivity or hyperactivity.
- Combined ADHD – if someone displays all or most of the above symptoms, they may be diagnosed with this type of ADHD.
First-line treatments usually involve stimulant medications, which can help people with ADHD focus on or initiate tasks. Cognitive behavioural therapy (CBT) is another popular ADHD treatment. CBT focuses on teaching skills that can help manage ADHD symptoms and show people with ADHD how to recognise and modify unhealthy behaviours.
ADHD is a complex and often misunderstood condition, and people with the condition sometimes turn to alcohol, illicit substances and other unhealthy coping mechanisms when they struggle to access treatments.
Does Medical Cannabis Have Any benefits for ADHD
Most of the positive evidence for using medical cannabis for ADHD is anecdotal or not clinically significant. There aren’t many recent, high-quality studies on the topic, but one randomised, controlled trial from 2017 found some positive results.
In the study, 30 adults with ADHD were given Sativex, a mouth spray containing tetrahydrocannabinol (THC) and cannabidiol (CBD), and found that the medication produced slight improvements to the patients’ impulsivity, hyperactivity, inattention and emotional instability. The improvements were only minor however, and the study was limited by its small sample size – but the results do support the need for further research on medical cannabis and ADHD.
Another more recent study found that among 59 study participants with ADHD, using medical cannabis, particularly cannabinol (CBN), may have helped reduce some ADHD symptoms. The study participants did self-report these improvements, meaning the results may have been biassed, and the lack of a control group means that the results aren’t as reliable.
Could Cannabis Cause or Worsen ADHD?
As to whether cannabis may have negative effects on ADHD, the research also isn’t conclusive. However, it does suggest that a cautious approach is best, especially when a person is under 25 with a still-developing brain.
A 2020 review found that people with ADHD may be more likely to use cannabis as a way of coping with their symptoms. The authors do admit that there are some flaws in these studies, so they don’t rule out the possibility that cannabis use may contribute to an ADHD diagnosis.
A 2023 review found the same genetic association between cannabis use and ADHD, while also noting that THC may have negative effects on executive function, which already tends to be impaired in people with ADHD. The review also highlights that adolescents should not use cannabis, as THC may alter a developing brain’s structure, and potentially cause issues later in life. This is why doctors will only prescribe medical cannabis to adolescents under highly specific circumstances.
It’s important to remember that medical cannabis, when used with a doctor's guidance, is usually safe. If you have ADHD, your prescribing doctor will take it into account when deciding if medical cannabis is right for you.
Discussing ADHD With Your Doctor
Currently, there isn’t enough evidence to suggest that medical cannabis is effective at managing ADHD. While there is some promising research, more robust and high-quality studies are needed, especially since using cannabis may pose risks for people with ADHD. Thankfully, there are medications and other treatments that are proven to be effective at managing ADHD.
If you suspect you have ADHD, book an appointment with your healthcare provider. Everyone is different, so it’s possible that medical cannabis may be appropriate for your unique circumstances, but your doctor will assess you and your condition and offer some treatment options.
