Acute Psychosis and Dissociative Syndrome Following Binge Recreational Nitrous Oxide Use: A Case Report

Abstract

Recreational nitrous oxide (N2O) inhalation is increasingly prevalent among young adults, but acute psychiatric presentations following short-term binge exposure remain poorly characterized. We report a case of a female in her early 20s with no prior history of psychotic illness who developed an acute psychotic and dissociative syndrome over three days at an outdoor music festival. Her presentation followed heavy recreational N2O and 3,4-methylenedioxymethamphetamine (MDMA) exposure combined with sleep deprivation. On admission, she exhibited profound disorientation, inability to recognize close family members, polymorphic delusions, passivity phenomena, and auditory and olfactory hallucinations, requiring involuntary psychiatric hospitalization. Diagnostic workup revealed normal brain and cervical spine magnetic resonance imaging (MRI) and a normal electroencephalogram (EEG) without epileptiform activity or slowing. Serum homocysteine was moderately elevated (25.2 µmol/L) alongside a low-normal vitamin B12 concentration (270 pg/mL), consistent with N2O-induced functional cobalamin deficiency; both markers normalized following parenteral vitamin B12 and oral folic acid supplementation. During inpatient stay, treatment with risperidone was followed by progressive neutropenia, which fully resolved after cross-titration to aripiprazole. She gradually regained full insight, was discharged on day 12, and remained free of psychotic symptoms at her three-week outpatient review. This case suggests that short-term binge N2O exposure, together with MDMA and sleep deprivation, may contribute to severe neuropsychiatric presentations without chronic use; it illustrates the value of measuring homocysteine rather than relying solely on serum B12 levels; and highlights potential hematological adverse effects during antipsychotic initiation.