# Highly purified cannabidiol (CBD) in CDKL5 deficiency disorder (CDD): Open-label prospective study. > **Author:** Benjamin Caplan, MD (ABFM Board Certified, MA Lic. #240562, NPI: 1962722637) > **Publisher:** CED Clinic (https://cedclinic.com) > **Canonical URL:** https://cedclinic.com/cbd-cdkl5-deficiency-disorder-treatment-research/ > **Published:** 2026-04-27T22:24:00-04:00 | **Last Modified / Clinically Audited:** 2026-09-28T10:00:29-04:00 > **Clinical Summary:** New research on CBD for CDKL5 deficiency disorder shows 89% patient retention over 12 months, suggesting potential as treatment option for this rare epilepsy. --- CED Clinical Relevance  #75Notable Clinical Interest Evidence Brief | CED ClinicHighly purified CBD demonstrated sustained tolerability in 8 of 9 children with CDKL5 deficiency disorder over 12 months, though seizure efficacy data were not quantified in this open-label study. Cdkl5[Pediatric Epilepsy](https://cedclinic.com/credit-rating-stability-pharmaceutical-cannabis/)Cbd[Rare Disease](https://cedclinic.com/advancing-rare-neurodegenerative-diseases-research/)Open-Label Trial Highly purified CBD demonstrated sustained tolerability in 8 of 9 children with CDKL5 deficiency disorder over 12 months, though seizure efficacy data were not quantified in this open-label study. What This Study Teaches Us This study demonstrates that highly purified CBD can be tolerated long-term in children with CDKL5 deficiency disorder, a severe epileptic encephalopathy. The 89% retention rate suggests acceptable tolerability, though the abstract does not provide seizure frequency reduction data or quantified clinical improvement measures. Why This Matters CDKL5 deficiency disorder causes intractable seizures and profound developmental disability with limited treatment options. Any intervention that patients can tolerate for a full year represents a meaningful finding for families facing this devastating condition. Study Snapshot Study Type Open-Label Prospective Study Population 9 patients with CDKL5 deficiency disorder, all female, median age 10 years (range 1-24) Intervention Highly purified cannabidiol (CBD) Comparator None (open-label design) Primary Outcome Motor seizure frequency, Clinical Global Impression scores, sleep, motor abilities, and EEG changes Key Finding 8 of 9 patients completed 12-month study (89% retention rate) Journal Epilepsia Open Year 2024 Clinical Bottom Line CBD appears tolerable in children with CDKL5 deficiency disorder based on high study completion rates. However, without seizure frequency data or quantified clinical outcomes in this abstract, efficacy cannot be assessed from these results. What This Paper Does Not Show The abstract provides no seizure frequency reduction data, no quantified clinical improvement measures, and no safety profile details. Without a control group, any clinical benefits cannot be attributed specifically to CBD versus natural [disease progression](https://cedclinic.com/multiple-sclerosis-biomarkers-p21-protein-variations/) or placebo effects. Where This Paper Deserves Skepticism Open-label design introduces significant bias potential, and high retention rates do not necessarily indicate clinical benefit. The small sample size (n=9) and lack of quantified efficacy outcomes limit the strength of any conclusions about CBD’s therapeutic value. Dr. Caplan's Take I need to see the actual seizure data before drawing conclusions about CBD’s efficacy in CDKL5 deficiency. High retention rates suggest families found value in continuing treatment, but that could reflect hope rather than measurable benefit. The abstract’s omission of seizure frequency results is concerning for a study designed to evaluate antiepileptic effects. What a Careful Reader Should Take Away This study suggests CBD is tolerable in CDKL5 patients, but provides insufficient efficacy data for [clinical decision-making](https://cedclinic.com/cannabinoids-mental-health-systematic-review-evidence-insights/). The high retention rate may indicate family satisfaction, but without seizure frequency data or quantified clinical measures, therapeutic benefit remains unestablished. Join the Conversation Have a question about how this applies to your situation? [Ask Dr. Caplan →](https://benjamincaplan.com/ask-dr-caplan) Want to discuss this topic with other patients and caregivers? [Join the forum discussion →](https://cedclinic.com/interact/discussion-forums/) Have thoughts on this? Share it: [X Share on X](https://twitter.com/intent/tweet?text=Just%20read%20this%20on%20CEDclinic.com%3A%20Highly%20purified%20cannabidiol%20%28CBD%29%20in%20CDKL5%20deficiency%20disorder%20%28CDD%29%3A%20Open-label%20prospective%20study.%20%40drcaplan&url=https%3A%2F%2Fcedclinic.com%2Fcbd-cdkl5-deficiency-disorder-treatment-research%2F)[in Share on LinkedIn](https://www.linkedin.com/sharing/share-offsite/?url=https%3A%2F%2Fcedclinic.com%2Fcbd-cdkl5-deficiency-disorder-treatment-research%2F)[🦅 Share on BlueSky](https://bsky.app/intent/compose?text=Just%20read%20this%3A%20Highly%20purified%20cannabidiol%20%28CBD%29%20in%20CDKL5%20deficiency%20disorder%20%28CDD%29%3A%20Open-label%20prospective%20study.%20via%20%40drcaplan.bsky.social%20https%3A%2F%2Fcedclinic.com%2Fcbd-cdkl5-deficiency-disorder-treatment-research%2F)[📷 Follow on Instagram](https://www.instagram.com/drbenjamincaplan)[📝 Read more on Substack](https://doctorapprovedcannabis.substack.com/)[🔔 Subscribe via RSS](https://cedclinic.com/feed/) Table of Contents - [FAQ](#FAQ)[What is the retention rate and tolerability of highly purified CBD in children with CDKL5 deficiency disorder?](#What_is_the_retention_rate_and_tolerability_of_highly_purified_CBD_in_children_with_CDKL5_deficiency_disorder) - [Does CBD effectively reduce seizure frequency in CDKL5 deficiency disorder?](#Does_CBD_effectively_reduce_seizure_frequency_in_CDKL5_deficiency_disorder) - [What age range of patients with CDKL5 deficiency can be considered for CBD treatment?](#What_age_range_of_patients_with_CDKL5_deficiency_can_be_considered_for_CBD_treatment) - [What non-seizure symptoms of CDKL5 deficiency disorder were evaluated during CBD treatment?](#What_non-seizure_symptoms_of_CDKL5_deficiency_disorder_were_evaluated_during_CBD_treatment) - [How is CBD dosing monitored in patients with CDKL5 deficiency disorder?](#How_is_CBD_dosing_monitored_in_patients_with_CDKL5_deficiency_disorder) - [Related](#Related) ## FAQ #### What is the retention rate and tolerability of highly purified CBD in children with CDKL5 deficiency disorder? This study demonstrated an 89% retention rate (8 of 9 patients) at 12 months, indicating good tolerability of highly purified CBD in children with CDD. The sustained use over 12 months suggests that CBD was generally well-tolerated in this pediatric population with drug-resistant seizures. #### Does CBD effectively reduce seizure frequency in CDKL5 deficiency disorder? While the study measured motor seizure frequency as a primary outcome, specific quantified seizure reduction data were not provided in this summary. The open-label design and small sample size (9 patients) limit the ability to draw definitive conclusions about seizure efficacy compared to controlled trials. #### What age range of patients with CDKL5 deficiency can be considered for CBD treatment? This study included patients aged greater than 1 year, with participants ranging from 1 to 24 years (median age 10 years). All participants were female, which reflects the X-linked inheritance pattern typical of CDKL5 deficiency disorder. #### What non-seizure symptoms of CDKL5 deficiency disorder were evaluated during CBD treatment? The study assessed multiple comorbidities beyond seizures, including sleep disturbances, motor abilities, and overall clinical improvement using caregiver and clinician-rated scales. EEG changes were also monitored at 3, 6, and 12-month intervals to evaluate neurophysiological effects. #### How is CBD dosing monitored in patients with CDKL5 deficiency disorder? CBD plasma levels were measured using High-Performance Liquid chromatography-Mass Spectrometry (HPLC-MS) to ensure appropriate dosing and monitor drug levels. This pharmacokinetic monitoring helps optimize therapeutic dosing while minimizing potential [adverse effects](https://cedclinic.com/physician-concerns-cannabis-health-effects-washington/) in this vulnerable pediatric population. 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