Inhaling a brief, high-concentration bolus of nitrous oxide produces short-lived subjective effects including increased ratings of 'high,' 'tingling,' 'stimulated,' and 'confused,' along with greater euphoria and psychedelic-like effects, especially at 40% and 80% concentrations. These effects typically dissipated within minutes. Psychomotor performance measured 2.5 minutes after inhalation did not differ from baseline, though the timing of measurement may have missed peak effects. The findings align with the recreational appeal of nitrous oxide.
Breathing 30% nitrous oxide in oxygen, compared to 100% oxygen, substantially impaired memory in 32 participants (16 men and 16 women). The memory impairments were less severe when tested with forced-choice recognition than with yes/no recognition, and for certain stimuli such as the first names of each participant's close relatives. Other variations in test procedures and stimuli did not affect the impairments. Nitrous oxide also produced numerous subjective effects, including some characteristic of psychedelic drugs, though standard subjective rating scales detected only sedation, not other mood effects.