Accuracy of self-report and toxicological assays to detect substance misuse disorders in parasuicide patients.

To assess the accuracy of self-reported substance use and toxicological assays in subjects admitted for Intentional Drug Overdose (IDO), using as a reference diagnosis of substance use disorder.Self-reported substance use was collected and toxicological assays were carried out in urine samples in 507 patients with IDO. A standardized psychiatric evaluation was performed in 100 randomly selected subjects.In routine practice, the emergency department staff did not investigate substance use in nearly one of two patients. Patients' statements and toxicological assays were more specific than sensitive, with lower scores for toxicological assays. Patients' statements made it possible to detect nearly 80% of subjects with substance use disorder.Identification of substance use disorder in subjects with IDO has strong clinical consequences regarding treatment and prevention of suicidal behaviour. Thus, emergency department staff should be made aware of the value of more systematically exploring self-reported substance use.