The prolonged or compulsive use of cocaine in any of its purified forms can cause severe personality disturbances, inability to sleep, and loss of appetite. A toxic psychosis can develop involving paranoid delusions and disturbing tactile hallucinations in which the user feels insects crawling under his skin. Cocaine abuse, which had been a marginal drug problem throughout much of the 20th century, grew alarmingly in the late 20th century in several countries, and cocaine has become responsible for a markedly increased proportion of drug-induced deaths