Do Trials Show Reduced Antipsychotic Use with Cannabis?

PostedMarch 12, 2026

UpdatedMarch 12, 2026

ByMy Patient Advice

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

There is growing interest in whether medical cannabis could help manage behavioural symptoms of dementia and, in turn, reduce the need for antipsychotic medications. However, according to NHS and NICE guidance, no clinical trials have shown that cannabis-based medicines consistently reduce antipsychotic use in dementia or other cognitive disorders (NHS Guidance; NICE NG97; NICE NG144).

What The Research Shows

Most studies of cannabinoids in dementia have investigated their effects on agitation, anxiety, and sleep, rather than on reducing prescribed medications. A 2023 double-blind crossover trial in older adults with dementia found no significant reduction in antipsychotic or sedative use among participants treated with cannabinoids compared with placebo (PubMed Study).

A 2024 Swiss feasibility study of THC/CBD oil in severe dementia reported that while some patients became slightly calmer, there was no consistent decrease in the need for other psychotropic medications (Swiss Study). Researchers concluded that evidence remains too limited to suggest cannabis could replace or reduce standard pharmacological treatment.

Systematic reviews published between 2023 and 2025 support this finding: although small improvements in agitation were noted, these effects were not strong or sustained enough to justify reducing antipsychotic doses (Systematic Review).

What Guidelines Say

The NHS, NICE, and Alzheimer’s Society UK all state that cannabis-based medical products are not recommended for managing behavioural or psychological symptoms of dementia and should not be used to replace antipsychotic medicines (Alzheimer’s Society). NICE surveillance reviews confirm that there is insufficient evidence of clinical benefit or safety to support changes in prescribing practice.

The Clinical Bottom Line

No randomised trials show reduced antipsychotic use from cannabis-based treatments.

Cannabinoids have shown only mild, inconsistent effects on agitation.

NICE and NHS do not recommend cannabis to replace or reduce other psychiatric medications.

Any potential use should occur only within clinical research trials, under specialist supervision.

Educational Context: AlleviMed

Educational organisations such as AlleviMed explain how medical cannabis eligibility is assessed in the UK. They highlight that licensed cannabis-based medicines are restricted to conditions such as epilepsy, chemotherapy-induced nausea, and spasticity in multiple sclerosis, not dementia or psychosis management.

Takeaway

Although some small studies suggest cannabinoids may slightly ease agitation, no evidence shows that cannabis reduces the need for antipsychotic medication in dementia. Current NHS and NICE guidance advises that cannabis-based products should not be used as a substitute for approved psychiatric treatments outside formal research trials.

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.