CONNECT-FX Used a Placebo Run-In Before Randomizing Children to CBD Gel
CONNECT-FX screened behavioral change during two weeks of single-blind placebo before randomization. The randomized population therefore represented more than children who met a diagnosis alone.
Improvement during run-in affected eligibility
Participants needed specified social-avoidance scores, with additional irritability criteria for some lower scores, and no more than 30% social-avoidance improvement during the run-in. Those criteria selected which children proceeded to CBD gel or placebo in the double-blind phase.
The comparison began after the run-in
The primary endpoint measured change from day one of randomized treatment to week twelve. It did not count the preceding placebo-run-in interval as CBD treatment. Randomization remained useful for comparing the subsequent groups, but the entry process affects which patients that comparison represents.
Selection did not eliminate the placebo response
The full-analysis primary between-group result was still nonsignificant. A run-in rule cannot be interpreted as proof that later placebo improvement disappeared or that every remaining change was pharmacological. It also limits direct extrapolation to families whose child improves substantially during an initial monitoring period. When discussing this trial, identify the pretreatment selection, the randomized baseline and the later endpoint separately. That preserves the actual design without assuming that placebo screening guarantees a positive treatment result.
Related analysis: the trial’s main results and limitations.
