If marijuana use was under-reported in the NESARC, this likely led to bias in the prevalence estimate of marijuana use disorder, because only those who report past-year use are assessed for marijuana use disorder. If under-reporting was more prevalent in the first wave of the NESARC than in the most recent wave (Wave 3), this could explain the apparent increase in the prevalence of marijuana use disorder. Trends in the past-year conditional prevalence of marijuana use disorder were similar across surveys, though NESARC estimates were substantially higher, suggesting that its diagnostic assessment is more sensitive than the one used in the NSDUH.1,4
