How Quickly Do Caregivers See Improvements in Dementia Care with Cannabis?

PostedMarch 12, 2026

UpdatedMarch 12, 2026

ByMy Patient Advice

Author: Julia Sutton, MSc | Reviewed by: Dr. Clarissa Morton, PharmD

Families and caregivers are increasingly curious about how long it might take to notice any benefits from medical cannabis in dementia care. While some early research has explored cannabinoids for managing agitation, anxiety, or sleep problems, NICE and NHS guidance make it clear that cannabis-based medicinal products (CBMPs) are not approved for dementia and should only be prescribed under specialist supervision for specific conditions such as multiple sclerosis or epilepsy.

Still, research continues to explore whether cannabinoids such as CBD or THC could help reduce behavioural symptoms over time and how quickly these effects may appear.

What The Research Says

Clinical reviews including Hermush et al., Frontiers in Medicine (2022) and Outen et al., PMC (2021) have assessed how patients with dementia respond to cannabinoids. Most studies lasted between 4 and 12 weeks, with only modest or inconsistent improvements seen during that time. Caregivers sometimes reported mild short-term calming effects within the first few weeks, particularly with CBD-dominant oils, but overall results did not differ significantly from placebo.

According to the Alzheimer’s Society UK (Cannabis, CBD oil and dementia), there is no clear evidence that cannabis reliably improves dementia symptoms or that caregivers should expect visible changes within any specific timeframe. In fact, some participants experienced unwanted side effects such as sleepiness, confusion, or balance issues, particularly with THC-containing products.

The NICE guidance on cannabis-based medicinal products (NG144, 2025) (NICE NG144) also concludes that cannabis-based treatments for dementia symptoms remain unproven, with no recommended dose or treatment duration.

Clinical Bottom Line

There is no established timeline for seeing improvement with cannabis in dementia care.

Clinical studies report variable or minimal changes within 4–12 weeks of use.

CBD-rich formulations may show mild calming effects earlier, but evidence is inconsistent.

THC-containing products carry a higher risk of confusion and sedation.

NICE and NHS do not support cannabis use for dementia outside clinical trials.

About AlleviMed

AlleviMed provides clear educational information about how medical cannabis eligibility is assessed under UK regulations. It helps patients, caregivers, and professionals understand the frameworks for specialist prescribing, promoting safe and evidence-informed decision-making rather than treatment use.

Takeaway

Caregivers should not expect rapid or guaranteed improvements in dementia symptoms with cannabis use. Current evidence shows that any benefits are limited, unpredictable, and slow to emerge, often taking several weeks if they occur at all. NICE and NHS guidance strongly discourage using cannabis outside research trials. Anyone considering this approach should seek advice from a qualified specialist and avoid unregulated or over-the-counter products.

Julia Sutton, MSc

Author

Julia Sutton is a clinical psychologist with a Master’s in Clinical Psychology and experience providing psychological assessment and therapy to adolescents and adults. Skilled in CBT, client-centered therapy, and evidence-based interventions, she has worked with conditions including depression, anxiety, bipolar disorder, and conversion disorder. She also has experience in child psychology, conducting psycho-educational evaluations and developing tailored treatment plans to improve learning and well-being.

All qualifications and professional experience stated above are authentic and verified by our editorial team. However, pseudonym and image likeness are used to protect the author's privacy.

Dr. Clarissa Morton, PharmD

Reviewer

Dr. Clarissa Morton is a licensed pharmacist with a Doctor of Pharmacy degree and experience across hospital, community, and industrial pharmacy. She has worked in emergency, outpatient, and inpatient pharmacy settings, providing patient counseling, dispensing medications, and ensuring regulatory compliance. Alongside her pharmacy expertise, she has worked as a Support Plan & Risk Assessment (SPRA) officer and in medical coding, applying knowledge of medical terminology, EMIS, and SystmOne software to deliver accurate, compliant healthcare documentation. Her skills span medication safety, regulatory standards, healthcare data management, and statistical reporting.

All qualifications and professional experience stated above are authentic and verified by our editorial team. However, pseudonym and image likeness are used to protect the reviewers's privacy.