Driving under the Influence of Psychotropic Substances: A Technical Interpretation

Abstract

This technical clinical and forensic note is designed to interpret the influence that psychoactive (or psychotropic) substances may have on driving. The present interpretation is restricted to the four groups of substances (i.e., cannabinoids, cocaine and metabolites, opiates and amphetamines and derivatives) outlined in Annex V of Ordinance No. 902-B/2007 of 13 August and it is expected that can be extrapolated to other jurisdictions besides Portugal. This work is presented in a pragmatic and objective way, avoiding the clinical, physiological, pathophysiological, and toxicological aspects that would hinder understanding and impair the usefulness and applicability of its content. The evaluation of the state of influence by psychotropic substances is a complex clinical and forensic subject especially due interindividual variability and concomitant consumption of other substances that may predispose to pharmacological interactions.