2012, Number 3
Consumo de alcohol y drogas en adolescentes evaluado a través del MMPI-A
Vinet EV, Faúndez X
Full text
Language: Spanish
References: 24
Page: 205-213
PDF size: 308.71 Kb.
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.
Adolescents were informed of the objectives and evaluation procedures, ensuring the confidentiality of information. Their participation was formalized by signing an informed consent form. EPG adolescents were administered the MMPI-A in their class group’s; while for CSC and CCC groups the MMPI-A was administered in small groups. The semi-structured interviews were conducted individually by the researchers; these interviews were aimed at corroborating the clinical condition of the participants and identifying and evaluating their drug consumption habits.
Data from the MMPI-A protocols were examined using the Mexican validity criteria, the responses were coded according to standard procedures to derive normative scores for clinical and substance abuse scales. Protocols A and B were coded by using an ad hoc criteria that allowed statistical analysis of information. To analyze group differences (CCC vs. EPG and CCC vs. CSC) Student t tests were used; whereas the analysis of the overall discriminating capacity of the scales was made by using ROC curve analysis, and the determination of discriminative cut-off scores between CCC and the contrast groups was made by using sensitivity and specificity analysis at different score levels.
The main results obtained in this study show that the MMPI-A scale is able to discriminate clinical adolescents with consumption from the clinical adolescents without consumption and from school attending adolescents from the general population, with no substance consumption nor clinical problems. The clinical scales’ scores were generally higher in the two groups from clinical origin than in the normal group. The supplementary scales, MAC-R, ACK, and PRO had a higher discriminatory capacity than the clinical scales. The highest discrimination capacity for the three scales was achieved by differentiating among the CCC group and the EPG group in both sexes; while the individual scale that achieved the best discriminatory capacity was the PRO scale. The evaluation of the ability to discriminate between groups CCC and CSC, and between these groups and group EPG, expressed in individual T scores showed that lower T scores (T55, T60) had greater discriminating power and that they privileged specificity (identification of non-use problems) over sensitivity.
The discrimination capacity of specific scores diminished when it came to distinguishing clinical cases with substance abuse problems from those with only clinical problems. Also the MAC and ACK scales were useful to distinguish between adolescents with problematic and unproblematic substance consumption. This phenomenon did not occur with the PRO scale.
These results support the use of the MMPI-A as a tool for comprehensive assessment of adolescents as it provides specific information on consumption that is likely to be analyzed in the context provided by the other 35 scales of the test. Also, these results encourage the study, adaptation and use of substance use scales in Latin American countries.
REFERENCES
Consejo Nacional para el Control de Estupefacientes. Octavo estudio nacional de drogas en población general de Chile. Santiago, Chile: Ministerio del Interior. 2008. Disponible en http://www.conace.cl/inicio/pdf/resumen_informe_VIII_estudio_drogas_poblaciongeneral_junio2009. pdf (recuperado 30 julio 2009).
Consejo Nacional para el Control de Estupefacientes. ¿Cómo sé si necesito tratamiento por mi consumo de drogas? Santiago, Chile: Ministerio del Interior. 2010. Disponible en http://www.conace.cl/portal/index.php?option=com_content&view=article&id=304:conacedrogascl-icomo-se-si-necesito-tratamiento-&catid=124:icomo-se-si-necesito-tratamiento (recuperado 20 octubre 2010).