title: Predominance of illicit drugs and poly-drug use among drug-impaired drivers in Sweden.
abstract: OBJECTIVE
  After Sweden's zero-tolerance law came into force (1 July 1999), the number of cases of driving under the influence of drugs (DUID) submitted by the police for toxicological analysis increased more than 10-fold. This prompted an in-depth investigation into the kinds of drugs used by DUID offenders, whether licit or illicit, and the frequency of their occurrence.
  
  
  METHODS
  All blood samples from DUID suspects sent by the police for toxicological analysis over a 4-year period (2001-2004) were investigated (N = 22,777 cases). Specimens of blood or urine were subjected to a broad screening analysis by immunoassay methods aimed at detecting amphetamines, cannabis, opiates, cocaine metabolite, and the major benzodiazepines. All positive results from the screening stage were verified by use of more specific analytical methods (e.g., GC-MS, LC-MS, GC-FID, and GC-NPD).
  
  
  RESULTS
  Between 80 and 85% of all the blood samples contained at least one banned substance and many contained two or more therapeutic and/or illicit drugs. About 15% of cases were negative for drugs, although these frequently (30-50%) contained ethanol above the legal limit for driving in Sweden, which is 0.20 mg/g (0.02 g%). Amphetamine was the most prominent illicit drug seen in 55-60% of cases either alone or together with other drugs of abuse. Stimulants like cocaine and/or its metabolite were infrequently encountered ( approximately 1.2% of cases). The next most prevalent illicit drug was cannabis, with positive results for tetrahydrocannabinol (THC) in blood either alone ( approximately 4%) or together with other psychoactive substances ( approximately 20%). Morphine, codeine, and/or 6-acetyl morphine were identified in approximately 2% of all DUID suspects, being indicative of heroin abuse. The major prescription drugs identified in blood were benzodiazepines (10%) as exemplified by diazepam, alprazolam, nitrazepam, and flunitrazepam. Drugs for treating insomnia, zolpidem and zopiclone, were also identified in blood samples from DUID suspects over the study period. Other therapeutic agents were encountered in only 1-2% of all cases.
  
  
  CONCLUSIONS
  The dramatic increase in DUID after the zero-tolerance law came into force probably reflects enhanced police activity and more enthusiasm to apprehend and charge individuals for this offence. Illicit drugs, particularly amphetamine and cannabis, and poly-drug use were predominant compared with use of scheduled prescription drugs. The typical DUID offender in Sweden abuses central stimulants, particularly amphetamine, and has probably done so over many years. Options for treating offenders for their underlying substance abuse problem should be considered instead of the more conventional penalties for drug-impaired driving.
authors.affiliation: Department of Forensic Genetics and Forensic Toxicology, National Board of Forensic Medicine, Artillerigatan 12, Linköping, Sweden.
authors.forename: Anita
authors.initials: A
authors.lastname: Holmgren
authors.forename: Per
authors.initials: P
authors.lastname: Holmgren
authors.forename: Fredrik C
authors.initials: FC
authors.lastname: Kugelberg
authors.forename: A Wayne
authors.initials: AW
authors.lastname: Jones
authors.forename: Johan
authors.initials: J
authors.lastname: Ahlner
mesh_terms: D000328:Adult; D001334:Automobile Driving / Q000331:legislation & jurisprudence; D005260:Female; D006801:Humans; D013287:Illicit Drugs / Q000097:blood / Q000145:classification* / Q000652:urine; D008297:Male; D015813:Substance Abuse Detection / Q000331:legislation & jurisprudence; D019966:Substance-Related Disorders / Q000453:epidemiology*; D013548:Sweden / Q000453:epidemiology
chemical_list: D013287:Illicit Drugs