For example, it there is comorbid other (or unknown) substance—induced depressive disorder and other (or unknown) substance use disorder, only the other (or unknown) substance— induced depressive disorder code is given, with the 4th character indicating whether the co- morbid other (or unknown) substance use disorder is mild, moderate, or severe: F19.14 for other (or unknown) substance use disorder with other (or unknown) substance—induced de- order with other (or unknown) substance—induced depressive disorder.
Specify current severity: 305.90 (F19.10) Mild: Presence of 2—3 symptoms.
304.90 (F19.20) Moderate: Presence of 4—5 symptoms.
304.90 (F19.20) Severe: Presence of 6 or more symptoms.
“In a controlled environment” applies as a further specifier of remission if the individual is both in remission and in a controlled environment (i.e., in early remission in a controlled environment or in sustained remission in a controlled environment). Examples of these environments are closely supervised and substance-free jails, therapeutic communities, and locked hospital units.
The diagnostic class other (or unknown) substance use and related disorders comprises substance-related disorders unrelated to alcohol; caffeine; cannabis; hallucinogens (phen- cyclidine and others); inhalants; opioids; sedative, hypnotics, or anxiolytics; stimulants (including amphetamine and cocaine); or tobacco. Such substances include anabolic ste- tihistamines; nitrous oxide; amyl-, butyl-, or isobutyl-nitrites; betel nut, which is chewed in many cultures to produce mild euphoria and a ﬂoating sensation; kava (from a South
Pacific pepper plant), which produces sedation, incoordination, weight loss, mild hepati- tis, and lung abnormalities; or cathinones (including khfit plant agents and synthetic chem- ical derivatives) that produce stimulant effects. Unknown substance-related disorders are associated with unidentified substances, such as intoxications in which the individual can- not identify the ingested drug, or substance use disorders involving either new, black mar- ket drugs not yet identified or familiar drugs illegally sold under false names.
Other (or unknown) substance use disorder is a mental disorder in which repeated use of an other or unknown substance typically continues, despite the individual’s knowing that the substance is causing serious problems for the individual. Those problems are re- ﬂected in the diagnostic criteria. When the substance is known, it should be reﬂected in the name of the disorder upon coding (e.g., nitrous oxide use disorder).
A diagnosis of other (or unknown) substance use disorder is supported 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.