Prevalence of psychoactive substances, alcohol, illicit drugs, and medicines, in Spanish drivers: a roadside study

Forensic Sci Int. 2012 Nov 30;223(1-3):106-13. doi: 10.1016/j.forsciint.2012.08.012. Epub 2012 Sep 1.


Following population, geographic, road type and time criteria, Spain has carried out random, roadside controls of 3302 representative sample of Spanish drivers, including saliva analysis for 24 psychoactive substances and alcohol breath tests. The 81.4% of the drivers were male, with an average age of 34.8±11.8 (mean±SD). The 17% of the drivers were found to be positive to any of the substances analysed. The 6.6% of the drivers found positive to alcohol (>0.05 mg/l in breath), 11% were found positive to any illicit drug, and 2% were positive to one of the medicines analysed. Some drivers were positive in more than one substance. The most common illicit drugs among Spanish drivers were cannabis (7.7%), or cocaine (3.5%), either alone or combined with other substances. The most prevalent medicines were the benzodiazepines (1.6%). As a tendency, higher figures for positive cases were observed among males than in females (being statistically significant the differences for alcohol, cannabis and cocaine). Alcohol and cocaine positive cases were more frequently found among drivers of urban roads. Alcohol positive cases (alone, >0.05 mg/l), were more likely found as age increase (OR=1.02), those driving in urban roads (OR=2.13), and driving at any period than weekdays, while alcohol+drugs cases were more likely found among males (OR=2.819), those driving on urban road (OR=2.17) and driving at night periods. Finding a medicines positive case was more likely as elder the driver was (OR=1.05). There have been differences in the prevalence of positive cases of alcohol, cannabis and cocaine, in relation to the period of the week: in three cases the highest prevalence seen in night time. This study shows the high prevalence of psychoactive substances and alcohol in Spanish drivers, mainly illicit drugs (cannabis). This question requires a response from the authorities and from society, with an integral and multi-disciplinary approach that can heighten the population's awareness of the risks of driving under the influence of certain substances.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age Distribution
  • Automobile Driving / legislation & jurisprudence
  • Automobile Driving / statistics & numerical data*
  • Benzodiazepines / analysis
  • Breath Tests*
  • Cannabinoids / analysis
  • Cannabis
  • Central Nervous System Depressants / analysis
  • Chromatography, Liquid
  • Cocaine / analysis
  • Ethanol / analysis
  • Female
  • Forensic Toxicology
  • Humans
  • Illicit Drugs / analysis
  • Logistic Models
  • Male
  • Middle Aged
  • Narcotics / analysis
  • Rural Population
  • Saliva / chemistry*
  • Sex Distribution
  • Spain / epidemiology
  • Substance Abuse Detection*
  • Substance-Related Disorders / epidemiology*
  • Tandem Mass Spectrometry
  • Urban Population
  • Young Adult


  • Cannabinoids
  • Central Nervous System Depressants
  • Illicit Drugs
  • Narcotics
  • Benzodiazepines
  • Ethanol
  • Cocaine