[High-risk drug use: epidemiological pattern through hair testing in the forensic context].

OBJECTIVE: The basic sources of information on drug use are epidemiological surveys, although they have some limitations: their results may be conditioned by the lack of veracity of the responses and the sampling method makes it difficult to detect lowprevalence behaviours in target populations. This study aimed to establish the epidemiological pattern of drug use in the population undergoing drug testing in hair, in the framework of judicial investigations, in order to provide an additional approach to the knowledge of high-risk drug use. METHODS: A cross-sectional study on drug use was conducted on the population subjected to drug testing in hair (N=5,292) in the forensic context. Prevalence of cannabis, cocaine, heroin, ketamine, amphetamine (AP), methamphetamine (MA), 3,4-methylenedioxy- methamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxy-N-ethylamphetamine (MDEA) and methadone uses were obtained. Association between drug use and demographics, and trends of prevalence over the period were analysed using the Pearson Chi-square test. Frequency distribution of drug concentrations in hair was obtained and it was assessed in relation to gender and age using the non-parametric Mann-Whitney U and Kruskal-Wallis H methods. RESULTADOS: En el periodo 2013-2015, la prevalencia de consumo de cocaina fue particularmente elevada (49%) en la poblacion estudiada, proxima a la de cannabis (54%). Las tasas de consumo de heroina, metadona, MDMA y anfetamina resultaron entre un 10% y mun 18%. Durante el periodo estudiado, se registro un aumento significativo del consumo de MDMA, heroina y anfetamina, asi como una disminucion significativa del consumo de metadona. CONCLUSIONES: Cannabis y cocaina son las drogas de abuso mas frecuentes entre la poblacion sometida a analisis de drogas en cabello en el marco de investigaciones judiciales en el periodo estudiado, si bien las proporciones de consumidores de heroina, MDMA y anfetamina muestran una tendencia creciente. Los patrones de consumo varian en funcion de la edad y del sexo, observandose disminucion del consumo de cannabis y MDMA e incremento del consumo de heroina y metadona al aumentar la edad. El consumo de cannabis, cocaina y MDMA resulta mas prevalente en hombres y el de metadona en mujeres.