The DSM-5 category called Substance-Related and Addictive Disorders includes two sub-categories: substance use disorders and substance-induced disorders. It is unfortunate these two terms sound so similar because they are quite distinct. Substance use disorders catalog the negative consequences of continued and frequent use of substances. These consequences are not immediate but occur over time as addiction progresses. In contrast, substance induced disorders refer to the immediate effects of substance use, called intoxication; and the immediate effects of discontinuing a substance, called substance withdrawal.
Substance Intoxication occurs when a person develops a reversible set of symptoms due to the recent use of (or exposure to) a substance. Symptoms of substance intoxication will vary according the substance. These specific symptoms are discussed within each substance-specific section. Intoxication occurs because chemical substances (such as drugs) directly affect the central nervous system. This leads to behavioral and/or psychological effects. Substance intoxication applies to all classes of drugs except tobacco. Typically, clinicians diagnose substance intoxication when someone arrives in an emergency room under the influence of alcohol or another drug.
Substance withdrawal is diagnosed based upon the behavioral, physical, and cognitive symptoms that occur due to the abrupt reduction or cessation of substance use. Like substance intoxication, these symptoms vary according to each specific substance. Therefore, these symptoms will be discussed within each substance-specific section. The use and discontinuation of some drugs do not result in withdrawal.
Diagnosing the severity of addictive disorders
In the substance-use section, we reviewed the 11 diagnostic criteria that may warrant a substance-use diagnosis. Withdrawal is one of the 11 criteria. Certain drugs do not have a significant withdrawal pattern associated with cessation or reduction of use. Drugs that do not cause withdrawal will have only 10 diagnostic criteria. In either case, to receive a diagnosis, person must have at least two of these 10 or 11 symptoms.
The DSM-5 uses a dimensional scale to estimate the severity of addiction. This scale based upon the total number of symptoms matching the diagnostic criteria. The scale ranges from mild-to moderate-to severe. Clinicians include this severity code as part of the diagnosis. In general, two to three symptoms indicate a mild substance use disorder. Four to five symptoms would ordinarily be called a moderate substance use disorder. If six or more symptoms are present, this would be classified as a severe substance use disorder.