Intoxication develops within minutes if the cannabis is smoked but may take a few hours to develop if the cannabis is ingested orally. The effects usually last 3—4 hours, with the duration being somewhat longer when the substance is ingested orally. The magnitude of the behavioral and physiological changes depends on the dose, the method of adminis- tration, and the characteristics of the individual using the substance, such as rate of absorp- tion, tolerance, and sensitivity to the effects of the substance. Because most cannabinoids, including delta-9—tetrahydrocannabinol (delta-9-THC), are fat soluble, the effects of canna- bis or hashish may occasionally persist or reoccur for 12—24 hours because of the slow re- lease of psychoactive substances from fatty tissue or to enterohepatic circulation.
The prevalence of actual episodes of cannabis intoxication in the general population is un- known. However, it is probable that most cannabis users would at some time meet criteria for cannabis intoxication. Given this, the prevalence of cannabis users and the prevalence of individuals experiencing cannabis intoxication are likely similar.
Functional Consequences of Cannabis Intoxication
Impairment from cannabis intoxication may have serious consequences, including dys- function at work or school, social indiscretions, failure to fulfill role obligations, traffic ac- cidents, and having unprotected sex. In rare cases, cannabis intoxication may precipitate a psychosis that may vary in duration.
Note that if the clinical presentation includes hallucinations in the absence of intact reality testing, a diagnosis of substance/medication-induced psychotic disorder should be con- sidered.
Other substance intoxication. Cannabis intoxication may resemble intoxication with other types of substances. However, in contrast to cannabis intoxication, alcohol intoxica- tion and sedative, hypnotic, or anxiolytic intoxication frequently decrease appetite, in- crease aggressive behavior, and produce nystagmus or ataxia. Hallucinogens in low doses may cause a clinical picture that resembles cannabis intoxication. Phencyclidine, like can— nabis, can be smoked and also causes perceptual changes, but phencyclidine intoxication is much more likely to cause ataxia and aggressive behavior.
Other cannabis-induced disorders. Cannabis intoxication is distinguished from the other cannabis-induced disorders (e.g., cannabis-induced anxiety disorder, with onset during intoxication) because the symptoms in these latter disorders predominate the clinical pre- sentation and are severe enough to warrant independent clinical attention.
Diagnostic Criteria 292.0 (F12.288)
A. Cessation of cannabis use that has been heavy and prolonged (i.e., usually daily or almost daily use over a period of at least a few months).
B. Three (or more) of the following signs and symptoms develop within approximately 1 week after Criterion A:
Irritability, anger, or aggression.
Nervousness or anxiety.
Sleep difficulty (e.g., insomnia, disturbing dreams).
Decreased appetite or weight loss.
Restlessness.
Depressed mood.
At least one of the following physical symptoms causing significant discomfort: ab- dominal pain, shakiness/tremors, sweating, fever, chills, or headache.
.‘IP’S’IPPNT‘
C. The signs or symptoms in Criterion B cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.
D. The signs or symptoms are not attributable to another medical condition and are not better explained by another mental disorder, including intoxication or withdrawal from another substance.