Laboratory validation study of drug evaluation and classification program: ethanol, cocaine, and marijuana

Area of Science:

• Forensic Science
• Toxicology
• Behavioral Science

Background:

• The Drug Evaluation and Classification (DEC) program is widely used by law enforcement to identify drug impairment.
• The program's validity in accurately identifying specific drug classes has not been extensively validated.

Purpose of the Study:

• To assess the validity of DEC evaluation variables in predicting the administration of ethanol, cocaine, or marijuana.
• To evaluate the accuracy of trained Drug Recognition Examiners (DREs) in detecting these drug classes.

Main Methods:

• A double-blind, randomized, within-subjects design was employed with 18 community volunteers.
• Participants received placebo or controlled doses of ethanol, cocaine, or marijuana across nine sessions.
• DEC evaluations and blood toxicology were conducted, with plasma drug concentrations measured.

Main Results:

• DEC evaluation variables accurately predicted the intake of ethanol, cocaine, and marijuana, particularly when using 17-28 specific variables.
• Drug Recognition Examiner (DRE) accuracy in identifying drug classes other than ethanol was 44% when compared to toxicology.
• Plasma drug concentrations were generally maximal during the DEC evaluation, except for marijuana.

Conclusions:

• The DEC evaluation demonstrates validity in predicting the acute administration of ethanol, cocaine, and marijuana.
• Improving DRE accuracy may be achieved by focusing on a refined subset of DEC variables.
• Further research may enhance the reliability of drug impairment assessments by law enforcement.