 Due to its perception @-@ altering effects , the onset of narcosis may be hard to recognize . At its most benign , narcosis results in relief of anxiety – a feeling of tranquility and mastery of the environment . These effects are essentially identical to various concentrations of nitrous oxide . They also resemble ( though not as closely ) the effects of alcohol or marijuana and the familiar benzodiazepine drugs such as diazepam and alprazolam . Such effects are not harmful unless they cause some immediate danger to go unrecognized and unaddressed . Once stabilized , the effects generally remain the same at a given depth , only worsening if the diver ventures deeper . 
