Cannabinoid-based interventions for behavioral outcomes in children and adolescents with autism spectrum disorder: A systematic review of safety and effectiveness.
Vasconcelos et al.·Progress in neuro-psychopharmacology & biological psychiatryImpact 3.4
MixedGRADEHigh0 citations
Samplek = 12 Studien
Durationunclear
ControlPlacebo
EndpointClinical Global Impression
Blindingunklar
DesignSystematic Review
Cannabinoidvollspektrum
THC:CBD20:1
”Key finding
Responder rates for global improvement showed a benefit (49% vs 21%), but standardised outcomes were predominantly not significant; evidence remains limited.
Summary
Systematic review on cannabinoids in children/adolescents with autism; k=12 studies (4 RCTs, 8 non-RCTs), 6 ongoing trials identified. Predominantly full-spectrum extracts with CBD:THC ratio 20:1, titration up to ~10 mg/kg/day. Responder rate for global improvement vs. placebo 49% vs. 21%; improvement in social communication. No between-group differences for sleep or overall symptomatology; repetitive behaviours showed a non-significant trend. Adverse effects mostly mild (somnolence, appetite changes, sleep problems, irritability); no serious treatment-related events. GRADE certainty very low.
P
PopulationChildren and adolescents with autism spectrum disorder (ASD)
I
InterventionCannabinoid-based interventions, mainly CBD and CBD:THC combinations (often 20:1 extracts, titration up to approx. 10 mg/kg/day)
C
ControlPlacebo (in RCTs); no control (in observational studies)
O
OutcomeGlobal improvement rate 49% vs. 21% (verum vs. placebo) and improved social communication in one RCT; no significant difference in sleep, overall symptomatology or repetitive behaviours; adverse events mostly mild (somnolence, appetite changes, sleep problems, irritability)
Confidence in the evidence
Very lowLowModerateHigh
High
The highest of four GRADE levels, the effect estimate is very reliable.
Quality profile
Sample size★★★★★
Blinding—
Effect sizeMixed
Citations / year★★★★★
Authors
Vasconcelos QDJS, de Freitas RF, Freitas MC, de Andrade IP, Brandao CB, Nascimento CE, Neves KR, Magalhaes PS, Filho VB, Oliveira GL
Background: Autism spectrum disorder (ASD) lacks effective options for core symptoms. Cannabinoids, especially cannabidiol (CBD) and combined CBD:Delta9-tetrahydrocannabinol (THC) formulations, are of interest, but clinical evidence is heterogeneous.
Purpose: To evaluate the effectiveness and safety of cannabinoid-based interventions for behavioral outcomes in children and adolescents with
Asd. Methods: Six databases (Scopus, Web of Science, Embase, Cochrane Library, PubMed, PsycINFO) were searched from February 2024 to June 2025. Risk of bias was assessed using RoB 2 (randomized controlled trials [RCTs]) and the Newcastle-Ottawa Scale (non-RCTs); certainty was evaluated with
Grade. Results: Twelve studies (4 RCTs, 8 non-RCTs) were included; six ongoing trials were identified. Most interventions used full-spectrum extracts with high CBD:THC ratios (often 20:1), with titration up to approximately 10 mg/kg/day; doses varied across studies. Responder rates for global improvement vs placebo (49% vs 21%) and greater improvement in social communication. No between-group differences were observed for sleep or overall symptom severity, and repetitive behaviors showed a non-significant trend toward improvement. Non-RCTs studies suggested benefits but had high risk of bias and very low certainty. Adverse events were mostly mild and non-serious (e.g., somnolence, appetite changes, sleep problems, irritability); no treatment-related serious adverse events were reported.
Conclusions: Evidence remains limited. A whole-plant 20:1 extract improved global clinical impression and social communication in one RCT, whereas other standardized outcomes were null. Current data support only cautious, adjunctive use under medical supervision. Larger, well-designed RCTs using validated outcomes are needed to clarify efficacy, optimal formulations, and long-term safety. PROSPERO registration: CRD42024508518.