Placebo-Controlled
A study design in which the control group receives an inert substance (placebo) identical in appearance to the active treatment, to account for the placebo effect.
In Depth
Placebo control is particularly challenging in cannabis research because THC's psychoactive effects make true blinding difficult — participants can often identify whether they received active treatment. This "unblinding" can inflate apparent treatment effects. Researchers have used low-dose active placebos, expectancy manipulation, and crossover designs to address this. CBD studies face less blinding challenge due to its non-psychoactive nature.
Related Terms
More in Research Methods
Randomized Controlled Trial (RCT)
The gold standard study design in clinical research. Participants are randomly assigned to treatment or control groups to minimize bias and establish causation.
Systematic Review
A structured synthesis of all available evidence on a specific research question, using predefined criteria to identify, evaluate, and summarize studies.
Meta-Analysis
A statistical technique that combines quantitative data from multiple studies to produce a pooled estimate of effect size with greater statistical power than any individual study.
Observational Study
A study in which researchers observe participants without intervening. Includes cohort studies, case-control studies, and cross-sectional surveys.
Bioavailability
The fraction of an administered dose that reaches systemic circulation in an active form. Varies substantially by route of administration for cannabinoids.