Psychosis and low cyanocobalamin in a patient abusing nitrous oxide and cannabis

Nitrous oxide (N2O) is an inhalant used primarily as anesthesia in dental procedures. It also has been reported as a substance of abuse among adolescents and young adults with a lifetime prevalence ranging between 2% and 15.8%. Abuse, or even occupational N2O exposure, 3,4 can cause vitamin B12 (cyanocobalamin) deficiency. Several case studies have also reported myelopathy, myeloneuropathy, and subacute combined degeneration in abusers of N2O, and even possible related deaths. To date, however, there have been only a handful of case studies of psychosis in a person abusing N2O. 12–14 We report a case of paranoid delusions and vitamin B12 deficiency in a man abusing N2O “whippits” along with cannabis.