Associated Features Supporting Diagnosis
A diagnosis of other (or unknown) substance us e disorder is supporte d by the individual’s
statement that the substance involved is not among the nine classes listed in this chapter; by re-
curring episodes of intoxication with negative results in standard drug  screens (which may not
detect new or rarely used substances); or by the presence of symptoms characteristic of an un-
identified substance that has newly appeared in the individual’s community.
Because of increased access to nitrous oxide (“laughing ga s”), membership in certain
populations is associated with diagnosis of ni trous oxide use disorder. The role of this gas
as an anesthetic agent leads to misuse by so me medical and dental professionals. Its use as
a propellant for commercial products (e.g., whipped cream dispensers) contributes to
misuse by food service workers. With recent  widespread availability of the substance in
“whippet” cartridges for use in home whipped cream dispensers, ni trous oxide misuse by
adolescents and young adults is significant, especially among those who also inhale vola-
tile hydrocarbons. Some continuously usin g individuals, inhaling from as many as 240
whippets per day, may present with serious medical complications and mental conditions,
including myeloneuropathy, spinal cord su bacute combined degeneration, peripheral
neuropathy, and psychosis. These conditions are also associated with a diagnosis of ni-
trous oxide use disorder. 
Use of amyl-, butyl-, and iso butyl nitrite gases has been  observed among homosexual
men and some adolescents, especially those with conduct disorder. Membership in these
populations may be associated with a diagnosis of amyl-, butyl-, or is obutyl-nitrite use dis-
order. However, it has not been determined that these substances produce a substance use