Dependence or abuse syndromes associated with regular or episodic use of chemical substances. Substance use disorders are recognized for alcohol; amphetamine; caffeine; cannabis; cocaine; hallucinogens; inhalants; nicotine; opioids; phencyclidine (PCP); sedative, hypnotic, or anxiolytic drugs; and combinations of drugs (polysubstance). Specific disorders include dependence (for all of the above-mentioned substances except caffeine) and abuse (for all except caffeine and nicotine).