INTRODUCTION

Nitrous oxide is widely used for recreational purposes, leading to constantly increasing cases of severe use disorder. Although the scope of the deleterious consequences of nitrous oxide use is relatively well described for neurological and thromboembolic-related complications, this is not the case in the psychiatric field.

CASE PRESENTATION

We report the case of a 20-year-old woman who developed nitrous oxide-induced peripheral neuropathy. The patient had a history of frequent nitrous oxide use. One year later, she presented with catatonia linked to nitrous oxide use, associated with vitamin B12 deficiency and hyperhomocysteinemia, with no apparent psychiatric causes. Nine months after the catatonic episode, she experienced a psychotic episode linked to long-term nitrous oxide use.

DISCUSSION AND CONCLUSION

To the best of our knowledge, this is the first report describing a cascade of neurologic and psychiatric complications of chronic use of nitrous oxide. Hyperhomocysteinemia caused by nitrous oxide consumption could explain the occurrence of such events. Homocysteine, methylmalonic acid, and active vitamin B12 are key biomarkers to determine the involvement of nitrous oxide in psychiatric symptoms.