Usefulness of hair analysis and psychological tests for identification of alcohol and drugs of abuse consumption in driving license regranting

The implementation of the points-based driving license helps to change the drivers' behavior and is related to a reduction of traffic accidents and fatalities. In Spain, when a driver loses all points, the driving license is revoked, so the driver must enroll on a Driver Awareness and Re-education (DARE) course. However, at the moment offenders are not submitted to any test to confirm absence of alcohol or drugs of abuse consumption, even when 9% of Spanish drivers lose their driving license for driving under the influence (DUI). The objective of this pilot study was the comparison of the usefulness of psychological tests and hair analysis to identify those individuals with a chronic consumption of alcohol and drugs of abuse among drivers performing DARE courses. Volunteers were submitted to the AUDIT and DAST-10 tests. Also a hair sample was collected and analyzed for ethylglucuronide (EtG) (LOQ 5 pg/mg) and 35 licit and illicit drugs (LOQ 5-50 pg/mg) by LC-MS/MS. Sixty-one participants with a mean age of 37.2 ± 11.6 years, and mainly men (90.2%), were recruited and performed AUDIT and DAST-10 tests. All hair samples were analyzed for EtG and 17 samples for licit and illicit drugs. Mean AUDIT score was 9.6 (SD = 7.5), showing a value ≥8 (indicator of hazardous and harmful alcohol use) in 52.4% of cases. Mean DAST-10 score was 2.9 (SD = 3.3), but a score ≥6 was detected in 21.3% of cases (indicating drug abuse or dependence). Twenty-two samples were positive for EtG, 8 for drugs of abuse (8 cocaine, 2 opioids, 1 amphetamines, 1 cannabis), and 3 for medicines. EtG concentration (20.7-1254.1 pg/mg) was higher than the Society of Hair Testing (SoHT) cut-off for chronic alcohol consumption (≥30 pg/mg) in 21 cases. All positive cases for methadone and cannabis, and half of positive cases for opioids and cocaine presented higher concentrations than SoHT cut-offs for chronic consumption. Higher AUDIT score and higher EtG concentration in hair were statistically associated with declaration of alcohol consumption ≥4 times/month and with previous fine for DUI of alcohol. In addition, AUDIT scores and EtG concentration in hair had a moderate but significant Spearman correlation (r = 0.331, p < 0.05). The combination of psychological tests and hair analysis seems to be a promising tool to identify individuals with chronic and problematic consumption of alcohol and drugs of abuse. Moreover, their application during driving license regranting procedures could increase the effectiveness of DARE courses, reduce recidivism and improve road safety.