Neuropsychiatric disorders associated with recreational nitrous oxide use

Abstract

Background

Recreational nitrous oxide use has grown in popularity among young people and has become a serious public health problem. Chronic use of nitrous oxide can lead to a functional vitamin B₁₂ deficiency and neuropsychiatric complications.

Purpose

This study aimed to investigate the characteristics of neuropsychiatric complications associated with nitrous oxide use and to enhance clinicians’ awareness of this public health problem.

Methods

We retrospectively reviewed 16 patients with neuropsychiatric disorders related to nitrous oxide use who were treated in our hospital from June 2021 to October 2022. Their demographics, clinical features, investigations, treatments and outcomes were analyzed.

Results

There were ten males and six females between the ages of 17 and 25 with a mean age of 20.5 ± 2.6 years. Thirteen patients sought medical help from the neurology clinic. Two patients presented to the psychiatric department and one patient presented to the emergency department with acute cognitive impairment. All 16 patients presented with neurological symptoms, such as paresthesia in four limbs or the lower limbs, unsteady gait and weakness. Twelve patients developed psychiatric symptoms, such as hallucinations, agitation, depression, emotional indifference and personality changes. Twelve patients had vitamin B₁₂ deficiency. All 16 patients had hyperhomocysteinemia. Fourteen patients showed abnormal high signal on T2-weighted imaging and an inverted “V” sign in axial view, mainly involving the cervical cord. Neuropsychiatric symptoms improved with vitamin B₁₂ treatment and cessation of nitrous oxide use in all cases.

Conclusion

Young adults are predominately involved in recreational use of nitrous oxide, which can cause neuropsychiatric complications. The clinical response to vitamin B₁₂ supplementation and cessation of nitrous oxide use is generally good. Clinicians should recognize nitrous oxide use as a public health problem and a cause of a wide range of neuropsychiatric symptoms, particularly in younger patients.

Keywords:

• Nitrous oxide
• homocysteine
• vitamin B₁₂
• neurological damage
• psychiatric symptoms

Author contributions

WHJ designed the study and wrote the manuscript. XLY and ZXYP performed the literature search and data analysis. ZXY wrote the study concept and design, and undertook critical revision of the manuscript. ZYJ and SY were responsible for study supervision. All authors read and approved the final manuscript.

Ethical approval

This study was approved by the Ethics Committee of Lianyungang First People’s Hospital (No. KY-20230706002-01).

Informed consent

Written informed consent was acquired from all participants or their legal guardians.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Scientific Research Fund of Jiangsu Provincial Elderly Health [LKM2023043].