Nitrous Oxide (N2O)-Induced Acute Psychosis.

Nitrous oxide (N2O), commonly referred to as laughing gas, is a colourless, non-flammable, inorganic volatile with psychedelic effects. It has assorted uses among diverse fields: in medicine and dentistry, N2O provides a source of dissociative anaesthesia and analgesia; in the food and automobile industries, N2O serves as a propellant in whipped cream canisters and as an engine booster, respectively. N2O is inexpensive and readily available at supermarkets as gas cylinders and dispensers for soda streams and whipped cream. It is among the top five most common inhalants abused by adolescents in the United States of America. A questionnaire-based study completed in New Zealand noted that 12% of first-year students at the University of Auckland inhaled N2O recreationally, and 3%used it at least monthly. Even though most people have an unremarkable, or even unpleasant, experience with N2O intoxication, some find the dissociative encounter euphoric, with associated sensations of “floating”, body tingling, warmth and numbness. Various cases of N2O abuse have surfaced in the literature, although isolated psychiatric presentations are uncommon. As cessation from N2O exposure and treatment with vitamin B12 usually lead to complete resolution of psychiatric symptoms, it is important to consider such a precipitant when a patient presents with neuropsychiatric manifestations of an uncertain etiology, especially when N2O use is obtained on history.