Consumo de alcohol y drogas en adolescentes evaluado a través del MMPI-A / Alcohol and drugs use in adolescents assessed through the MMPI-A

ABSTRACT

Currently, the consumption of alcohol and drugs is a major public health problem worldwide due to its high social and economic impact. In Chile, the highest prevalence and greatest drug consumption rates occur in young people aged 19 to 25 years. Adolescence is the most vulnerable development stage for starting drug use. The latest study from CONACE (Chilean National Council for Drugs Control) in school population indicates that 15.1% of students report having used marijuana in the past year, while 33% admitted current use of tobacco and 36% of alcohol. Drug use among adolescents is exacerbated upon verification of its relationship with other risk behaviors as law transgressions, sexual promiscuity, teenage pregnancy and family difficulties. This situation has led various theorists to develop psychological assessment tools to specifically detect and evaluate drug use in adolescence. Among the instruments for psychological assessment, self-report measures have been the most widely used method to evaluate the use of alcohol and other drugs and their associated problems. One of the greatest strengths of self-report measures is that they can detect problems related to drugs in people who for various reasons would like to hide their status of substance abusers. The Minnesota Multiphasic Personality Inventory for Adolescents (MMPI-A) is one of the best self-report instruments for clinical assessment in adolescent population. The MMPI-A consists of 478 items with True and False response format and it has three scales that specifically detect substance abuse problems; they are MacAndrew's Alcoholism Scale Revised (MAC-R, in Spanish MAC-A), Alcohol/Drug Problem Acknowledgement Scale (ACK, in Spanish RPAD) and Alcohol/Drug Problem Proneness Scale (PRO, in Spanish TPAD). In Chile, there is a MMPI-A version which has empirical studies that support its use with general population Chilean adolescents. These studies also highlight the usefulness that MAC, ACK and PRO scales could have to provide detailed information on specific features that would impact on the use of alcohol and drugs. The aim of this study was to examine the ability of the MMPI-A Chilean version to detect substance abuse problems in specific settings. Its objectives were 1. to determine the applicability of MAC-R, ACK and PRO scales in different samples of Chilean adolescents, 2. to evaluate the ability of these scales to discriminate problematic substance use in adolescents with and without other clinical problems, and 3. to propose discriminative cut-off scores for the indicated scales. In order to accomplish these goals, we used a quantitative methods approach with a descriptive correlational design for three independent groups. The sample comprised 74 adolescents (44 males and 30 females) with clinical problems that had substance use, diagnosed according to the CONACE criteria for unproblematic consumption categories (occasional and habitual consumption) and DSM-IV criteria for problematic use (abuse and dependence). This group was named "clinical adolescents with consumption" (CCC). Using this group as reference, we selected two additional contrasting groups a group of adolescents with clinical problems but without substance use called "clinical adolescents without consumption" (CSC; n=71), and a group of school adolescents from general population without substance consumption problems nor other psychopathological problems that would warrant clinical attention called "school-youngsters from general population" (EPG; n=74). The total sample (n=219) had an average age of 16.3 years (SD=1.3) and was collected in urban centers located in south-central Chile. Two instruments were used The Minnesota Multiphasic Personality Inventory for Adolescents (MMPI-A), which provides the three scales for the assessment of substance abuse the MAC-R scale is a revision of the MAC scale, originally developed by MacAndrew to distinguish alcoholic from non-alcoholic psychiatric outpatients; the other two scales were developed for the assessment of alcohol and other drugs problems among adolescents. Specifically, the ACK scale was a rationally constructed scale of 13 items with obvious content relating to alcohol or other drug use; while the PRO scale was a 36-item scale constructed empirically by selecting items with no-obvious content related to substance uses that discriminated between adolescents who were in treatment for substance abuse and normal adolescents, or adolescents in clinical treatment. In addition, the clinical MMPI-A scales were used as a supplementary measure. The second instrument was a semi-structured clinical interview based on two clinical guides called protocols A and B. Protocol A allows for doing a clinical interview with adolescents starting from two open-ended questions that inquire reasons for consultation and information on family structure and dynamics. It also checks symptoms in six areas including school, behavioral, emotional, physical, sexual and interpersonal symptoms. Behavioral symptoms include the checking out for consumption of alcohol and drugs. Those adolescents who respond positively to the consumption of alcohol and drugs must answer Protocol B. This is a clinical guide of ad hoc construction, based on the criteria used by the CONACE for the diagnosis of non-problematic use of substances and the DSM-IV criteria for diagnosis of drug abuse and dependence.

RESUMEN

En la actualidad, el consumo de alcohol y drogas es uno de los mayores problemas de salud pública en el mundo, debido a su alto costo social y económico. En Chile, las prevalencias más altas y la mayor intensidad en el consumo de drogas se registran en los jóvenes de 19 a 25 años, siendo la adolescencia la etapa más vulnerable para el inicio del consumo de drogas. El último estudio del CONACE (Comisión Nacional de Control de Estupefacientes) en población escolar señala que 15.1% de los estudiantes chilenos declaran haber consumido marihuana en el último año, mientras que 33% reconoce un consumo actual de tabaco y 36% de alcohol. El consumo de drogas en adolescentes se agrava al comprobarse su relación con otras conductas de riesgo, lo que plantea la necesidad de desarrollar instrumentos de evaluación psicológica que consideren el consumo de drogas en la adolescencia de modo específico. Entre los instrumentos de evaluación psicológica, las medidas de autorreporte han sido el método más utilizado para evaluar el uso de alcohol y drogas, pues permiten detectar este problema en personas que por diferentes motivos desearían esconder su condición de abusadores de sustancias. Uno de los instrumentos de autorreporte es el Inventario Multifásico de la Personalidad de Minnesota para Adolescentes (MMPI-A) el cual posee tres escalas que evalúan el consumo de alcohol y drogas Alcoholismo de MacAndrew Revisada (MAC-A; en inglés, MAC-R), Reconocimiento de Problemas con el Alcohol y/o Drogas (RPAD; en inglés, ACK) y Tendencia a Problemas con el Alcohol y/o Drogas (TPAD; en inglés, PRO). Aunque en Chile existe una versión en español de la prueba y estudios empíricos que respaldan su uso con adolescentes chilenos, no se había estudiado su funcionamiento con adolescentes consumidores de drogas, lo cual motivó el desarrollo de la presente investigación. Los objetivos del estudio fueron 1. conocer el comportamiento de las escalas MAC-A, RPAD y TPAD en diferentes muestras de adolescentes chilenos, 2. evaluar la capacidad de estas escalas para discriminar el consumo problemático de sustancias en adolescentes con y sin otros problemas clínicos y 3. proponer puntajes de corte discriminativos para las escalas señaladas. La muestra está compuesta por 74 adolescentes (44 hombres y 30 mujeres) con problemas clínicos que presentaban consumo de sustancias, diagnosticado según los criterios del CONACE para las categorías de consumo no problemático (ocasional y habitual) y del DSM-IV para el consumo problemático (abuso y dependencia). Este grupo fue denominado adolescentes Clínicos Con Consumo (CCC). A partir de él se seleccionó a dos grupos de contrastación un grupo de adolescentes consultantes por problemas clínicos pero sin consumo de sustancias, los cuales fueron denominados adolescentes Clínicos Sin Consumo (CSC) y un grupo de adolescentes escolarizados de población general sin problemas de consumo ni otros problemas psicopatológicos que ameritaran una consulta clínica, denominados adolescentes Escolares de Población General (EPG). Los principales resultados de este estudio muestran que el MMPI-A es capaz de discriminar a los adolescentes clínicos consumidores de drogas de los adolescentes clínicos sin consumo y de los escolares de población general. Las puntuaciones de las escalas clínicas en general son superiores en los dos grupos de procedencia clínica que en el grupo normal. Las escalas suplementarias, MAC-A, RPAD y TPAD, poseen una capacidad de discriminación muy alta; la mayor capacidad de discriminación de las tres escalas se logra al diferenciar entre los adolescentes del grupo CCC y los del grupo EPG en los dos sexos, siendo TPAD la que mejor discrimina. Además, cabe destacar la utilidad de MAC-A y RPAD para distinguir entre adolescentes con consumo problemático y no problemático. Estos resultados demuestran la utilidad del MMPI-A para evaluar a adolescentes chilenos con sospecha de consumo de drogas e incentivan el estudio, adaptación y utilización de este instrumento en Latinoamérica.