Taking your medication as directed, but still finding it hard to stay focused, regulate emotions or get through a full day without losing the thread. If this describes where you are, it does not mean you have failed treatment. ADHD is complex, and medication that does not work well enough for one person at one point in time may need review, not replacement. This article explains what a proper medication review involves and what medical cannabis for ADHD in the UK setup can and cannot offer when that review has not resolved things.
Key Takeaways
- If ADHD medication is not working, the first step is to contact the clinician who prescribes it, not to change it independently.
- Dose, timing, formulation, sleep, co-existing anxiety and other health factors can all affect how medication performs.
- Current evidence for medical cannabis in ADHD is limited and mainly observational. It does not establish cannabis as an ADHD treatment.
- A private medical cannabis assessment is individual and does not guarantee a prescription.
- Never stop or adjust ADHD medication without clinical advice.
When ADHD medication is not working, what should happen next?
When ADHD medication is not working, contact the clinician who prescribes it before making any changes. A review should look at benefit, side effects, adherence, sleep quality, substance use, physical health, and whether a co-existing condition such as anxiety or depression may be affecting how the medication feels. Do not stop ADHD medication suddenly. ¹ NICE recommends ongoing structured review of ADHD medicines, including assessment of benefit and unwanted effects. ² Changing dose, timing or formulation should be clinician-led. A structured review of what is and is not working is more useful than switching without a plan.
Medical cannabis for ADHD UK: what does the evidence show?
Research into medical cannabis for ADHD in the UK is early and limited. The available evidence from the UK Medical Cannabis Registry ADHD cohort is observational. It reported associations with changes in health-related quality of life, sleep quality and anxiety measures in adults with ADHD who were prescribed CBMPs in routine clinical practice. ³ This data cannot establish that CBMPs caused those changes, distinguish the effect of cannabis from other life or care changes during the same period, or confirm that ADHD core symptoms improved. This is not a randomised controlled trial. ³ The Medical Cannabis Clinicians Society notes that evidence for cannabis in ADHD remains insufficient to support it as an established treatment, and that assessments in this population require particular care given psychiatric risk factors. ⁴
Why ADHD symptoms can feel worse even when you are taking medication
ADHD medication often works differently across the day. Dose wearing off in the afternoon, poor sleep amplifying distractibility, anxiety layered on top of ADHD, low mood reducing motivation, work or study pressure increasing demands beyond what medication can buffer, all of these can make someone feel their medication has stopped working when the medication itself has not changed at all. Hormonal changes in women across the menstrual cycle can also affect how stimulant medicines perform, and this is underrecognised.
Co-existing conditions are particularly common in people with ADHD and frequently go unrecognised. Anxiety affects a significant proportion of adults with ADHD and responds to different treatment than the ADHD itself. ¹ A proper review identifies these layers before concluding that the medication needs replacing.
When a UK specialist may discuss medical cannabis for ADHD
A private medical cannabis assessment in the UK may be discussed only in the context of a person’s full clinical history. Cannabis is not a first-line ADHD treatment and should not be presented as one. A specialist would consider a patient’s full diagnosis and records, treatment history, other medicines including ADHD medications, psychiatric history, substance use history, and safety factors including driving, machinery and work responsibilities.
To understand what records are relevant, our guide to what medical records to bring to a cannabis consultation covers this in detail.
A specialist may also explore whether medical cannabis could be assessed alongside treatment for a co-existing condition such as persistent insomnia or chronic pain, rather than as a direct ADHD treatment. Not every patient who asks will be found suitable, and a specialist may advise against it.
Consider an adult with a formal ADHD diagnosis who has tried a stimulant with limited benefit and a non-stimulant that caused side effects they could not tolerate long-term. Persistent anxiety and poor sleep are affecting their ability to work. They have followed clinical advice throughout. This is the kind of history a specialist would want to review carefully. It does not indicate what the outcome would be.
For more on which conditions may qualify for medical cannabis in the UK, our eligibility guide explains the general assessment framework.
Safety, driving and medicine interactions
ADHD medicines and cannabis must be reviewed together by a clinician. Some CBMPs can interact with stimulant and non-stimulant ADHD medicines. Cannabis containing THC can affect alertness, reaction time and mood, which matters for driving, work safety and daily responsibilities. You must not drive if you feel drowsy, dizzy, impaired or otherwise affected, regardless of whether your prescription is legal. If you drive as part of your work or daily life, discuss this explicitly during any assessment. Do not attempt to combine prescribed ADHD medication and cannabis without specialist oversight.
What care at LeafEase involves
LeafEase is a private medical cannabis clinic. Assessments are conducted by video with GMC-registered specialist clinicians who review your full records, treatment history and safety factors before any prescribing decision. LeafEase does not diagnose ADHD and does not prescribe cannabis as an ADHD treatment. If a CBPM prescription is considered appropriate, medication is delivered to your home in plain, discreet packaging with no indication of the contents on the outside. LeafEase Advantage provides continuity with the same clinician, follow-up consultations, reviews built around your daily routine, and free home delivery.
If you have a formal diagnosis, have followed clinical advice and want a specialist to review your history, you can check your eligibility. This does not replace a review of your ADHD medication with the clinician who prescribes it.
Frequently Asked Questions
Can adults with ADHD get medical cannabis in the UK?
A private specialist may consider a CBPM assessment for an adult with ADHD, but medical cannabis is not an established ADHD treatment and is not guaranteed. Assessment is individual and considers diagnosis, treatment history, psychiatric history and safety factors.
Is medical cannabis a replacement for ADHD medication?
No. Medical cannabis should not be treated as a substitute for prescribed ADHD medication. Any decision to change ADHD treatment must be made with the clinician managing that care, not independently.
Can you take ADHD medication and medical cannabis together?
This is a clinical question that requires specialist oversight. Some interactions are possible. Never combine them without the knowledge of both the clinician managing your ADHD and the specialist who may prescribe a CBPM.
References
1] NHS (2023) Attention deficit hyperactivity disorder (ADHD): treatment. Available at: https://www.nhs.uk/conditions/attention-deficit-hyperactivity-disorder-adhd/treatment/ Accessed: September 2026].
2] National Institute for Health and Care Excellence (2019) Attention deficit hyperactivity disorder: diagnosis and management. NICE Guideline NG87. Available at: https://www.nice.org.uk/guidance/ng87 Accessed: September 2026].
3] Ittiphakorn, S. et al. (2023) UK Medical Cannabis Registry: an analysis of clinical outcomes of medical cannabis therapy for attention-deficit/hyperactivity disorder. Neuropsychopharmacology Reports. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC10739081/ Accessed: September 2026].
4] Medical Cannabis Clinicians Society (2024) Medical cannabis and mental health: evidence, clinical judgment and responsible prescribing. Available at: https://www.ukmccs.org/guidance-publications/medical-cannabis-and-mental-health-evidence-clinical-judgment-and-responsible-prescribing Accessed: September 2026].
