Cannabis Use Disorder 511
Synthetic oral formulations (pill/capsules) of delta-9-tetrahydrocannabinol (delta-9-
THC) are available by prescripti on for a number of approved medical indications (e.g., for
nausea and vomiting caused by chemotherapy; for anorexia and weight loss in individuals
with AIDS). Other synthetic cannabinoid co mpounds have been manufactured and dis-
tributed for nonmedical use in the form of plant material that has been sprayed with a can-
nabinoid formulation (e.g., K2, Spice, JWH-018, JWH-073). 
The cannabinoids have diverse effects in the brain, prominent among which are actions
on CB1 and CB2 cannabinoid receptors that ar e found throughout the central nervous sys-
tem. Endogenous ligands for these receptor s behave essentially like neurotransmitters.
The potency of cannabis (delta-9-THC concentration) that is generally available varies
greatly, ranging from 1% to approximately 15% in typical cannabis plant material and
10%–20% in hashish. During the past two de cades, a steady increase in the potency of
seized cannabis has been observed. 
Cannabis is most commonly smoked via a variety of methods: pipes, water pipes
(bongs or hookahs), cigarettes (joints or reefer s), or, most recently, in the paper from hol-
lowed out cigars (blunts). Cannabis is also sometimes ingested orally, typically by mixing
it into food. More recently, devices have be en developed in which cannabis is “vapor-
ized.” Vaporization involves heating the plant material to release psychoactive cannabi-
noids for inhalation. As with other psychoactive substances, smoking (and vaporization)