Psychological changes induced in normal volunteers by inhalations of nitrous oxide are deacribed. Some of these changes resembled psychiatric symptoms, for example illusions and hallucinations, perseverations, and 'dissociated' states.There was no relation between individual differences in the number of changea reported, ratings for emotional stability, and cognitive impairment attributable to the drug.Possible relations between normal, drug-induced, and other forms of abnormal behaviour are discussed.* The subject's handwriting had deteriorated, and she waa leaving letters like 'a' and ' 0 ' partly open. t Corrugated rubber tubing which connected the subject's face maak with the anaesthetic machine.$ A male technician.
8The aubject waa at that time searching for a suitable reaearch project for her Ph.D.