FAAH Genotyping Did Not Identify CBD Pain Responders in a Small Clinical Trial
The spinal-cord-injury trial did not find a significant association between the tested FAAH variants and treatment response. Its small genotyped sample did not establish a genetic test for selecting CBD responders.
The mechanistic question was specific
The researchers examined two FAAH single-nucleotide variants and assessed associations with response using a dominant genetic model. FAAH participates in endocannabinoid metabolism, providing a rationale for the investigation. Thirty-three participants completed genotyping.
Biological plausibility did not become prediction
The reported genotype–response analyses were nonsignificant. This does not prove that genetics cannot influence CBD response, but it does mean the study did not demonstrate reliable patient selection using these variants. A plausible pathway and a validated predictor require different evidence.
Keep the subgroup denominator attached
The genotyping analysis involved fewer people than the randomized trial as a whole. Small samples can miss associations and produce unstable estimates. The overall modest pain finding cannot be relabeled a genotype-specific effect without the corresponding evidence. These measurements also concerned genetic variation, not THC exposure testing or direct measurement of brain endocannabinoid concentrations. The supported conclusion is a limited mechanistic null, alongside a need for larger investigations before clinical prediction claims.
Related analysis: the study’s broader findings and limitations.
