Over half the Danish population had used illegal psychotropic drugs, with cannabis being the most common and not significantly linked to quality of life. Cocaine, amphetamine, and psilocybin were used by 1.2% to 3.3% of the population, with a small but clear variation in quality of life. LSD users, 1.2% of the population, had a quality of life score 10% lower than non-users. The lowest quality of life was among users of heroin, morphine, methadone, and a mixture of alcohol and tranquilizers, scoring 10–20% below the highest quality of life group.
Abusing stimulant drugs like MDMA disrupts sleep-wake patterns because they promote arousal and prevent sleep. MDMA can also damage brain serotonin neurons in animals and possibly humans, and serotonin helps regulate sleep and circadian rhythms. People with MDMA-induced serotonin damage may develop chronic sleep and circadian problems, which could contribute to other issues like memory disturbances seen in abstinent users. This review examines preclinical and clinical studies on how prior MDMA exposure affects sleep, circadian activity, and the circadian pacemaker, identifies knowledge gaps, and suggests future research directions.