Role of Cannabis in Managing ADHD

Alternaleaf Team
Written by
Alternaleaf Team
May 23, 2024
Last updated:
Jun 7, 2024

ADHD is everywhere.

Between 2000 and 2018, among men aged 18-29 alone, there was a 20-fold increase in ADHD diagnoses. The same is true for drug prescriptions. A 50x jump.

And, given this data came before the recent wave of greater ADHD awareness and resulting media frenzy (both mainstream and social), plus the long wait people face for a proper assessment, this may only hint at the full picture.

Now, as UK medication supplies run dry (at the same time cannabis clinics see a colossal rise in ADHD patients), many are asking:

‘Can medical cannabis help ADHD symptoms?’

Let’s find out.

What is ADHD?

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental condition that affects how someone thinks and behaves.

Broadly, this plays out in three ways:

  • Hyperactive and impulsive: Loud, restless, can be disruptive.
  • Inattentive: Easily distracted, often bored, disorganised.
  • Combined type: A mix of the above.

Why are ADHD Diagnoses Soaring?

For years, diagnoses were far more common in boys, as they tend to show more stereotypical traits, like disruptive behaviour. This doesn’t mean fewer girls have ADHD, just that symptoms can be less obvious – e.g. day dreaming, or low self-esteem.

It’s estimated that 2.6 million people in the UK have ADHD, including 1.9 million adults.

Changes in diagnostic criteria, paired with better understanding of what ADHD looks like (especially among women), helps explain the recent surge in diagnoses, as well as the press coverage they spawned.

In short, many ADHDers went through childhood not knowing they had it – even though they suffered from symptoms.

While ADHD can be a strength (some claim it’s the source of their creativity or ‘outside-the-box’ thinking style), symptoms must negatively impact a person’s life, in two or more areas, to warrant diagnosis.

There is no ‘cure’ for ADHD. But, unlike other neurodivergent conditions such as autism and dyslexia, it can be treated.

Effects of Cannabis on ADHD

ADHD squarely exists in the brain. As such, cannabis compounds can potentially have a big impact. In particular:

  • Tetrahydrocannabinol (THC): The main psychoactive component, THC attaches itself to cannabinoid receptors across the nervous system and brain, and is what provides a ‘high’ or euphoric feeling.
  • Cannabidiol (CBD): The second-most common compound (after THC), CBD works on different parts of the brain. Non-psychoactive (i.e. no high), its popularity as an ingredient in all kinds of health product has rocketed of late.

Many assume CBD is the answer for all forms of therapeutic products, including for ADHD, largely as it’s non-psychoactive. In reality, THC and CBD have different upsides.

Both have anti-inflammatory qualities, can help ease anxiety, combat insomnia and relieve pain. There’s evidence CBD can limit seizures, whereas THC helps boost appetite.

As for what strain works best, science shows that rampant cross-breeding between cannabis strains has “rendered their distinctions meaningless in today’s marketplace.”

Anecdotally, people view indica-dominant strains as having a higher CBD content, versus sativa, which is associated with greater THC. This may help people target specific symptoms.

Cannabis and ADHD: Potential Benefits

Cannabis research on ADHD is limited, however some studies do exist.

  • For instance, a 2021 systemic review (that is, a paper that gathers all available evidence to answer a specific question) found no proof that cannabis has a negative impact on neurodevelopment in teens or young adults with ADHD. On the contrary, a 2023 study showed a link between cannabis products for ADHD and improvements in anxiety, sleep quality and quality of life – though it called for further study.
  • Not only that, new research found many higher education students with ADHD believe cannabis aids their studies. This echoes research from 2021 and 2016, where several ADHDers praised the positive effect of cannabis for a variety of things – including boosting focus, aiding relaxation, and reducing hyperactivity and impulsivity. Others said cannabis eased the side effects of ADHD medication, such as anxiety and irritability. In all three cases, the data is self-reported (making it subjective, not scientific), but provides a glimpse into how some people already use cannabis to manage ADHD.
  • Meanwhile, a small randomised control trial (hailed as the gold standard of clinical testing) in 2017 found adults who took the cannabinoid medication Sativex (which features both THC and CBD) had a small reduction in ADHD symptoms. That said, improvements were minor, and not much greater than placebo, which underscores the need for more research.

Cannabis and ADHD: Risks and Concerns

Despite some encouraging data, it’s important to keep things in context.

For example, research from 2020 found ADHDers who took a higher dose of medical marijuana were able to reduce their ADHD medication.

This could be positive, as there’s data that shows 19 out 20 of people who take such medication experience at least one side effect, like insomnia, irritability or loss of appetite (all of which cannabis is known to support).

Yet this ignores the potential side effects of cannabis itself. The plant affects everyone differently, and can cause any of the following issues:

  • Headaches
  • Drowsiness
  • Mood swings
  • Paranoia
  • Nausea
  • Upset stomach
  • Breathing issues (when smoked)

In the absence of more robust evidence, it’s not advised to self-treat ADHD with cannabis, supplement medication with marijuana, or swap one for the other. As always, it’s best to speak to a doctor in the first instance.

Can You Get Prescribed Medical Cannabis for ADHD?

Cannabis is a Class B drug, and remains illegal in the UK.

Since 2018, however, it has been a Schedule Two substance. This means specialist clinics can prescribe cannabis for medical purposes, provided it’s clinically appropriate and is in a patient’s best interest.

Put another way:

Cannabis-based medicines for ADHD are not available on the NHS. But if a patient and doctor agree that medical cannabis would improve their ADHD symptoms, a prescription is possible.


The whole ‘cannabis and ADHD’ debate can be boiled down to two key points:

  • There is promising data to suggest medical cannabis may improve ADHD symptoms.
  • But much, much more research is needed to prove this.

In the meantime, any ADHDer aged over 21 who wants to find out whether medical marijuana for ADHD might work for them (especially at a time that ADHD drug supplies remain stretched, UK-wide), the advice is simple:

Speak to a medical professional today.