Low-THC Cannabis Extract Shows Promise for Rett Syndrome Symptoms in Girls | Research

The takeaway

An open-label trial of 11 girls with Rett syndrome found a full-spectrum cannabis extract (0.08% THC) improved communication, alertness, anxiety, and quality of life over 12 weeks.

Rett syndrome families and clinicians, rare disease researchers

Socialization/eye contact improved with p = 0.0004

What the researchers found

NTI164 improved global clinical impression (p = 0.028), communication skills (p = 0.003), socialization/eye contact (p = 0.0004), attentiveness (p = 0.001), anxiety (p = 0.004), and quality of life (p = 0.0002) in 11 girls with genetically confirmed Rett syndrome over 12 weeks.

Why it matters

Rett syndrome is a severe neurodevelopmental disorder with very limited treatment options. While this is a small open-label study, the consistency of improvements across multiple validated outcome measures is noteworthy for a condition with few effective interventions.

The numbers in context

11 participants; improvements in communication (p = 0.003), eye contact/socialization (p = 0.0004), attentiveness (p = 0.001), anxiety (p = 0.004), quality of life (p = 0.0002), caregiver burden (p = 0.006).

How the study worked

Phase I/II open-label study of 11 female participants aged 5-16 years with pathogenic MECP2 variants. NTI164 administered twice daily for 12 weeks with multiple validated outcome measures.

What this study cannot tell us

Very small sample (n = 11) with no control group or blinding. Open-label design means placebo and caregiver expectation effects cannot be ruled out. 12-week duration may not capture long-term effects or tolerance.

How to read the evidence

Small open-label study without a control group, though it used genetically confirmed participants and multiple validated outcome measures.

When this study was published

2025 publication

The bigger picture

Several groups are exploring cannabinoid therapies for rare neurological conditions. Rett syndrome, caused by mutations in a single gene (MECP2), offers a relatively well-defined population for studying potential benefits.

Questions still open

Would a placebo-controlled trial confirm these improvements?
Which components of the full-spectrum extract are most responsible for the observed effects?

Common questions

Can cannabis help with Rett syndrome?

In this small open-label trial, a low-THC cannabis extract improved communication, eye contact, attention, anxiety, and quality of life in 11 girls with Rett syndrome. However, without a control group, placebo effects cannot be ruled out.

What type of cannabis product was used for Rett syndrome?

The study used NTI164, a full-spectrum medicinal cannabis extract containing only 0.08% THC, administered twice daily. It contains multiple cannabinoids beyond just CBD and THC.

Read the original research

Full-Spectrum Medicinal Cannabis Plant Extract 0.08% THC (NTI164) Improves Symptoms of Rett Syndrome: An Open-Label Study.

Journal of paediatrics and child health

View on PubMed ↗Publisher’s paper ↗

Citation

Keating, B A; Ogru, Y; Duthy, T G; Douglas, L; Lichkus, K; Isikgel, E; Fahey, M C; Ellaway, C. (2025). Full-Spectrum Medicinal Cannabis Plant Extract 0.08% THC (NTI164) Improves Symptoms of Rett Syndrome: An Open-Label Study.. Journal of paediatrics and child health. https://doi.org/10.1111/jpc.70122