Does nitrous oxide addiction exist? An evaluation of the evidence for the presence and prevalence of substance use disorder symptoms in recreational nitrous oxide users

Background: Prevalence of nitrous oxide (N2O) use appears to be increasing in numerous countries worldwide, and excessive use has been associated with physical and mental problems. Because there currently is no consensus whether N2O has addictive potential, we aimed to evaluate the evidence for the presence and prevalence of DSM-5 substance use disorder (SUD) symptoms in N2O users.Analysis: A literature search was conducted to assess the evidence for the presence of any of the 11 DSM-5 SUD symptoms in N2O users and the prevalence experiencing those symptoms. A substantial part of the studied N2O users use more than intended (i.e. 46% to 98%) and spend a substantial amount of time using N2O. At least some of the studied N2O users experience interpersonal problems (i.e. 13% to 80%) and use N2O in risky situations, such as driving under the influence. Evidence for the other criteria is either insufficient or inconclusive.Conclusions: The literature base for the presence and prevalence of DSM-5 substance use disorder (SUD) symptoms in nitrous oxide (N2O) users is limited and largely consists of qualitative studies and case studies, but it provides consistent evidence for the presence of at least four SUD criteria in heavy N2O users. N2O could well be addictive and should be treated as a potentially addictive substance until systematic assessments can provide evidence-based guidance to users, healthcare professionals and legislators.