Medical problems related to recreational drug use at nocturnal dance parties.

During 'I love techno' (edition 2001), an indoor rave party attended by 37 000 people, data about medical problems (especially drug-related problems) were collected. To place these data in a wider perspective, a similar registration was done during 'De Nacht', a traditional New Year's Eve dance party held at the same location and attended by 12 000 people. Furthermore, a prospective study on the time course of the level of consciousness (Glasgow Coma Score) and blood concentrations of illicit drugs, especially gamma-hydroxybutyrate was set up.