From their statement:
ASAM asserts that the significant public health problems and costs related to marijuana legalization are not well-understood by the public or policymakers. ASAM's conclusion that marijuana legalization would threaten public health is based on the following:
· Marijuana use is neither safe nor harmless. Marijuana contains psychoactive cannabinoids which can produce a sense of discomfort and even paranoid thoughts in some users. Cannabinoids interact with brain circuits in comparable ways to opioids, cocaine and other addictive drugs. Marijuana use is associated with damage to specific organs and tissues and impairments to behavioral and brain functioning.
· Of greatest concern is marijuana use during adolescence—a time of ongoing brain development and heightened vulnerability to addiction. Research shows that heavy marijuana use decreases neurocognitive performance, with worse neurocognitive effects seen among those who begin marijuana use early.
· Marijuana is addictive. Repeated marijuana use is reinforcing because the drug increases activation of reward circuitry in the brain. Approximately 9% of people who try marijuana become dependent. For those who begin using the drug in their teens, approximately 17% become dependent. These figures are similar to alcohol dependence.
· Legalization would promote the public perception that marijuana is harmless at the same time that availability of the drug would grow exponentially. The rate of marijuana use and marijuana-related substance use disorders, including addiction, would increase.
· Increased marijuana addiction would heighten demand for substance use disorder treatment services, which already are inadequate for current needs.
· Marijuana use is associated with increased rates, and worsening symptoms, of psychosis. Increased marijuana use caused by legalization and increased access to high-potency marijuana could result in rising rates of psychotic illnesses.
· Marijuana-related crashes are major traffic safety threats; marijuana use doubles the risk of a crash. Research inWashington State showed that 12% of drivers killed in car crashes were positive for marijuana. Legalization would increase drugged driving.