Neuropsychiatric sequelae of chronic nitrous oxide misuse in middle‐aged adults: A case series
Theodore Tsonis, Nassima Ait‐Daoud Tiouririne, Nathan P. Charlton, Avery Michienzi
American Journal on Addictions October 27, 2026 DOI: 10.1111/ajad.70220 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Case study Longitudinal Case report Peer reviewed |
|---|---|
| Sample size | 3 |
| Population | Middle-aged adults with chronic nitrous oxide misuse and neuropsychiatric presentations |
| Key findings | In three adults with chronic nitrous oxide misuse, homocysteine was markedly elevated in all, but vitamin B12, methylmalonic acid, hematologic indices, and outcomes varied. The authors report that biochemical abnormalities did not consistently correspond to clinical severity or recovery, and recommend assessing nitrous oxide exposure in unexplained neuropsychiatric presentations. |
Abstract
Abstract: Background and
Objectives: Chronic nitrous oxide (N 2 O) misuse causes heterogeneous neuropsychiatric toxicity.
Methods: We retrospectively reviewed three middle‐aged adults with chronic N 2 O misuse and neuropsychiatric presentations.
Results: Presentations included cognitive impairment, hallucinations, and variable neurologic dysfunction. Homocysteine was markedly elevated in all patients, while vitamin B12, methylmalonic acid, hematologic indices, and longitudinal outcomes varied. Discussion and
Conclusions: These cases illustrate heterogeneous biochemical and clinical trajectories, with biochemical abnormalities not consistently corresponding to clinical severity or recovery. Scientific
Significance: Clinicians should specifically assess N 2 O exposure in unexplained neuropsychiatric presentations and interpret cobalamin‐related biomarkers in clinical context.