Treatment Seeking Nitrous Oxide Users in Addiction Care: A Comparison with Cocaine Users on Clinical and Treatment Characteristics

Abstract

<b><i>Introduction:</i></b> Over the past decade, frequent use of large quantities of nitrous oxide (N₂O) has become more common in the Netherlands. Although N₂O poses several negative health consequences for a subgroup of problematic N₂O users, there is a lack of knowledge on what characterizes these intensive users. This study therefore aims to provide the demographic and substance use characteristics and experiences during treatment of treatment seeking problematic N₂O users and to compare this with a matched group of treatment-seeking problematic cocaine users. <b><i>Methods:</i></b> A retrospective chart review was performed of patients who were referred for treatment of problematic N₂O use at a large Dutch addiction care facility from January 2020 to September 2022, extracting demographics, pattern of use and follow-up data. Additionally, a subgroup of N₂O users was propensity-score matched (1:1) with a subgroup of treatment seeking problematic cocaine users, both groups excluding users with substance use disorders or frequent use of substances other than N₂O and cocaine, respectively. <b><i>Results:</i></b> 128 patients with a N₂O use disorder were included in the total sample and a subgroup of 77 N₂O-only users was propensity-score matched on age and sex to 77 cocaine-only users. N₂O users were typically young (mean age 26.2 years), male (66.4%), unmarried (82.9%), with a low education level (59.0%) and born in the Netherlands (88.2%), with parents born in Morocco (45.3%). N₂O was used intermittently (median 10 days/month, IQR 4.0–17.5 days) and often in very large quantities (median 5 kg [ca. 750 balloons] per average using day, IQR 2–10 kg). Compared to the patients with a cocaine use disorder, matched N₂O users were lower educated, more often from Moroccan descent, and less likely to be alcohol or polysubstance users. Despite receiving similar treatments, N₂O users were twice as likely to discontinue treatment before completion compared to cocaine users (63 vs. 35%, <i>p</i> = 0.004). <b><i>Conclusion:</i></b> Treatment-seeking problematic N₂O users are demographically different from treatment-seeking problematic cocaine users and are much more likely to dropout from psychological treatment. Further research is needed into the needs and other factors of problematic N₂O users that relate to poor treatment adherence in problematic N₂O users.