Abstract Introduction Marijuana is the world’s most widely used illegal drug. In Mexico, it is the drug of choice for both male and female users of all ages, and there has been a recent increase in its use. Objective To describe drug use trends in people seeking treatment by sex and age range, and to explore different patterns. Method To provide a description of trends and rates of increase for the population attended between 2005 and 2016 and to make a comparative analysis of patterns of use in a sample of 11 595 marijuana users who received treatment in 2016. Results In general, there has been a greater increase in use in the group ages twelve to seventeen. The greatest increase in lifetime use was reported among women in this age range. The greatest increase in marijuana use in the past month was found among women aged eighteen to thirty-five. Women use a greater variety of substances, and a higher number of younger women report using cocaine, methamphetamines, benzodiazepines and hallucinogens than men. Discussion and conclusion Significant increases in marijuana use have been registered among girls under 18 and women in recent years. The differences in trends and patterns of use for men and women are being reduced and reconfigured.
Resumen Introducción La mariguana es la droga de mayor consumo en el mundo. En México, es la droga preferida por ambos sexos y en todos los grupos de edad, y en su consumo ha habido un incremento desde hace varios años. Objetivo Describir las tendencias del uso de mariguana en solicitantes de tratamiento, por sexo y rango de edad, y explorar diferencias en el patrón de consumo, según sexo. Método Se describieron tendencias y tasas de crecimiento en población atendida entre 2005 y 2016 y se realizó un análisis comparativo del patrón de consumo con una muestra de 11 595 usuarios de mariguana recibidos para tratamiento en 2016. Resultados En general, se registran mayores tasas de crecimiento en el grupo de 12 a 17 años. El mayor incremento del uso alguna vez en la vida corresponde a las mujeres de este rango; el del uso en el último mes y como droga de mayor impacto, a las de 18 a 35 años. Las mujeres consumen un mayor número de sustancias. Las de menor edad refieren el uso de cocaína, metanfetaminas, éxtasis, benzodiacepinas y alucinógenos en mayor proporción que los hombres. Discusión y conclusión Los menores de edad y las mujeres tienen un mayor peso en el aumento del uso de mariguana registrado en los últimos años. Las diferencias en las tendencias y el patrón de consumo entre sexos se están reduciendo y reconfigurando.
Abstract: The aim of this study was to identify psychosocial correlates of harmful alcohol use among young Mexican students, and to comparatively prove the predictive validity of three theoretical models, each one capable to support the research of the problem and to guide the design of theoretically and empirically grounded preventive and treatment programs: a) the alcohol expectancies theory, b) the social learning theory by R. Akers, and c) the planned behavior theory. Findings indícate that these three models are appropriate predictive models for harmful alcohol use in the studied group. The highest predictive weight belongs to positive expectancies associated to the effects of alcohol, followed by alcohol use among friends, low risk perception, and self-control of alcohol drinking as a protective factor. Findings suggest the convenience of the application of a composed multi-varied algorithm, integrated by factors and variables extracted from the three models.
Resumen: El presente estudio se planteó como objetivo identificar correlatos psicosociales del consumo nocivo de alcohol en estudiantes mexicanos, así como probar comparativamente la validez y capacidad explicativa de tres modelos teóricos y de medición de estos factores, a fin de apoyar la investigación del problema y dar pauta al desarrollo de acciones preventivas teórica y empíricamente sustentadas. Estos tres modelos son: la teoría de las expectativas, la teoría del aprendizaje social de R. Akers y la teoría de la conducta planificada. Los hallazgos indican que los tres modelos tienen una buena capacidad predictiva del consumo nocivo de alcohol en la población de estudio. El mayor peso corresponde a las expectativas positivas asociadas a los efectos del alcohol, seguidas por el uso de alcohol entre pares, una baja percepción de riesgo y, como factor protector, la capacidad percibida para controlar la cantidad que se bebe. Los hallazgos reflejan la conveniencia de aplicar un modelo multivariado compuesto por variables provenientes de los tres modelos.
This paper shows the evaluation of the effectiveness of a selective prevention on drug use in adolescents, based on the Theory of Planned Behavior by Azjen. To develop this program, different theoretical models were evaluated considering their suitability to the institutional context in which it will be implemented. The criteria used to select a model that could be useful as a basis to design and evaluate a preventive intervention for drug use included: a) incorporation of protective and risk factors that could be malleable; b) consistency, parsimony and theoretical economy; c) a demonstrated explanatory and predictive capacity; d) empirical effectiveness; e) practical applicability. One of the models that complies with these requirements is the Model of Planned Behavior by Azjen, which proposes that the most immediate causes for drug use are the intentions of the subject to consume them or not. These intentions are determinated by the «attitudes» toward drug use, by the normative beliefs or «subjective norm» and by the Perceived Behavior Control. Attitudes toward the behavior are a person's overall evaluation of the behavior (i.e drug use) and the corresponding positive or negative judgments about it. The normative beliefs or subjective norms are a person's own estimate of social pressure to use or not to use drugs. Subjective norms have two interacting components: beliefs about how other people, who may be significant to the person, would like them to behave (normative beliefs), and the positive or negative judgments about each belief (outcome evaluations). Perceived behavioral control is the magnitude to which a person feels able to carry out the behavior. It includes two aspects: how much control a person has over the behavior; and how confident a person feels about being able to perform or not the behavior. It is determined by control beliefs about the power of both situational and internal factors to inhibit or facilitate the performance of the behavior. Perceived behavioral control, the last element introduced in the theory, along with the attitude to conduct, and the subjective norm, contribute, all of them, to predict the behavior intention. Generally speaking, there is important empirical evidence concerning the predictive and explicative capacity of this model in different populations. Once the theoretical model was chosen, indicators related to constructs of the Theory of Planned Behavior were elaborated adapting these constructs to the features of middle education Mexican population by means of a series of interviews with focal groups. Based on these indicators, a scale was constructed to prove the explanatory capacity of the theoretical model in Mexican population. The reliability and validity of this self-applied questionnaire was proved. Once this was done, based on these antecedents, the model was adapted in a practical sense. This means that the content, objectives and techniques for a preventive intervention were developed. This preventive intervention was piloted and then evaluated through the aforementioned scale. The program included attitudinal and normative components, conformed by informative strategies and persuasive messages directed to an attitudinal change, as well as the development of strategies of behavioral control focused on social abilities that included components derived from social learning theory, and a series of cognitive behavioral techniques accorded to the Planned Behavioral Theory. It was expected a reduction in the drugs use intention by means of a change of drug use favorable beliefs as well as reinforcing unfavorable beliefs of drug use. It was also tried to change the perception about the magnitude of drug users in the subject's immediate surroundings and on its perception about social acceptance or tolerance for drugs. Also it was tried to increase the perception of self control, in order to the develop behavioral control skills to refuse the offer of drugs. The first sessions (devoted to work on subjective norm) were directed to create an interest in the participants regarding to their relation with favorable situations to drug consumption, and to modify their perception about the real magnitude of drug use and about approval and social tolerance to them, both topics frequently overestimated for some adolescents. These sessions were also devoted to identifying beliefs associated with drug use and the value that participants give to these beliefs, in order to question those that are established upon false premises. The next sessions (devoted to perceived behavioral control) had as an objective to learn appropriated behavioral responses to confront risk situations, in order to increase the perception of self-control in those circumstances. This was achieved by means of modeling, essay and reinforcing techniques. This model was designed to be applied in groups no greater than 15 persons, twice a week in five sessions of 50 minutes each. The program was applied by professional personnel such as psychologists or social workers with previous experience in drugs use prevention. The program was implemented in three groups (one for each grade) of five high schools in Mexico City and was applied to three groups of school, randomly chosen; other three groups, in the same grades, were used as control groups. The groups were randomly chosen. Other three groups, in the same grades, were used as comparison groups. Then, the final sample was composed by 250 participants (96 from intervened groups and 154 from comparison groups) from 1 2 to 15 years old, and with slightly more men than women, but equivalent for cases and control. The results showed that the intervened group had a statistical significant reduction in the intention of drugs use. On the contrary, the comparative group showed an increasing intention to use them. With respect to the set of variables that predicted the behavioral intention, the perceived behavioral control stands out as the variable that had the greatest change. There were no significant differences in pre-post measures in the control group. Differences between pre-post measurements were also contrasted between both groups using a Student's /test that showed significant differences in perceived behavioral control and behavioral intention variables. Finally, in order to get a greater control on the test scores, an ANCOVA analysis was applied using the post-test scores as dependent variable and the pre-test scores as covariables. This analysis was useful to corroborate the significance of the drug use intention in the future, mainly in situations that require an amount of self-control, while attitude and normative variables did not show significative changes. Outcomes confirmed the pertinence to give greater resources (time, quantity, and complexity of activities, didactic materials, etc.) to the sessions devoted to developing behavioral control skills. These results can be considered satisfactory, because the main objective of the program was to reduce the intention to use drugs; however, it is also necessary to strengthen the attitudinal and normative components. It is necessary to consider that the variable «subjective norm» obtained the lowest levels in confidence, possibly because of the use of self-reported answers in a variable so sensitive to the influence of social elements. For this reason, it is necessary to develop questions that diminish this element that, according to Doll and Azjen, can explain, even a 5% of variance in «behavioral intention». Finally, it must be considered that this evaluation shows the effectiveness of the program to achieve the expected changes in behavioral intention variable only in controlled situations. It is necessary to investigate if it is possible to obtain similar results in more usual conditions and with other populations. This means that as well as to grant the internal validity of the evaluation it is also necessary to establish its external validity.
Se presentan los resultados de la evaluación de la eficacia de un programa de prevención selectiva del consumo de drogas para adolescentes, basado en la teoría de la conducta planificada de Ajzen. Para el desarrollo de este programa se identificaron y evaluaron distintos modelos teóricos. Los criterios considerados para seleccionar un modelo que pudiera servir de base para el diseño y evaluación de una alternativa de intervención preventiva del uso de drogas, teórica y empíricamente sustentada, comprendieron: a) la inclusión de factores de riesgo o protectores maleables; b) consistencia, parsimonia y economía teóricas; c) probada capacidad explicativa y predictiva; d) eficacia empírica; e) aplicabilidad práctica. Uno de los modelos teóricos que cumplen satisfactoriamente estos requisitos es el Modelo de la Conducta Planificada de Ajzen, el cual plantea que la causa más inmediata del uso de drogas son las intenciones del individuo respecto a consumirlas o no. Estas intenciones están determinadas a su vez por dos componentes; por una parte, las actitudes hacia el consumo, y por otra, las creencias normativas o norma subjetiva. Las actitudes están conformadas por el conjunto de creencias sobre las consecuencias del consumo y por el valor afectivo que tales consecuencias tienen para el sujeto. Las creencias normativas o norma subjetiva también están determinadas por dos componentes. Por un lado, la percepción de que otras personas significativas para el sujeto aprueban o desaprueban el consumo y, por otro, la motivación del sujeto para acomodarse a las expectativas o deseos de estas personas. El control conductual percibido, último componente introducido en la teoría, contribuye ¡unto con la actitud hada la conducta y la norma subjetiva a predecir la intención conductual. En general, se cuenta con importante evidencia empírica acerca de la validez predictiva y explicativa de este modelo, en relación con el consumo de drogas entre distintas poblaciones. Una vez elegido el modelo teórico se elaboró una escala de medición para probar su capacidad explicativa para el caso de uso de drogas en población mexicana. Probada la capacidad explicativa del modelo, se llevó a cabo su adaptación práctica, en términos de desarrollar contenidos, objetivos y técnicas de una intervención preventiva basada en el mismo. Por último, se realizó la prueba piloto y la evaluación de la aplicación controlada de tal intervención. La evaluación de resultados se apoyó en un diseño experimental con prueba-postprueba y un grupo control. El programa se aplicó en cinco escuelas secundarias de la Ciudad de México. Se intervino a tres grupos de cada escuela, uno por grado, elegidos aleatoriamente. La muestra final, una vez depurada, quedó conformada por 250 jóvenes (96 casos y 154 controles) de entre 12 y 15 años de edad. Para la evaluación se utilizó una cédula creada ex profeso y probada previamente en una muestra de 1 200 alumnos, mostrando buenos niveles de confiabilidad y validez. Los resultados muestran que en el grupo intervenido tuvo lugar una disminución estadísticamente significativa de la intención de usar drogas, en tanto que los alumnos del grupo comparativo mostraron, por el contrario, un incremento en la intención de uso durante el mismo lapso. Del mismo modo, entre las variables antecedentes de la intención conductual, a saber, actitud, norma subjetiva^ control conductual percibido, la variable que mostró un mayor cambio fue esta última. También se contrastaron las «puntuaciones de ganancia» (diferencias antes-después) del grupo de los casos contra las del grupo de los controles, con lo que se pudo observar que las diferencias significativas entre ambos grupos se presentaron en las variables control conductual percibido e intención conductual. Finalmente, mediante el Modelo Lineal General (MLG) ANCOVA, se pudo corroborar la significativa reducción de la intención de utilizar sustancias y el incremento en la percepción de autocontrol, mientras que la actitud y la variable normativa no mostraron cambios significativos, lo que confirma la pertinencia de haber dotado de mayores recursos (tiempo, número y complejidad de las actividades, materiales didácticos, etc.) a las sesiones dedicadas al desarrollo de habilidades de control conductual, sobre la base previamente probada, tanto en población anglosajona como entre jóvenes mexicanos, de que esta variable suele tener un mayor peso en la explicación de la intención de usar drogas.
OBJETIVOS: Identificar factores psicosociales de riesgo de consumo de sustancias ilícitas en estudiantes mexicanos y ofrecer elementos para el diseño de programas de prevención. MÉTODOS: Estudio transversal no experimental con una muestra de 516 estudiantes de secundaria y bachillerato de seis de las principales ciudades de México. Entre abril y junio de 2005 se aplicó una adaptación de la versión abreviada del Inventario de Tamizaje sobre el Consumo de Drogas (DUSI-R). El análisis comprendió ocho factores: abuso en el consumo de bebidas alcohólicas o drogas, malestar afectivo, bajo control conductual, baja adherencia escolar, baja competencia social, relaciones familiares disfuncionales, aislamiento social y pertenencia a redes sociales desviantes (cuyos integrantes consumen drogas y adoptan actitudes antisocia-les). Se identificaron factores de predicción del consumo de drogas ilícitas mediante regresión logística y se elaboró un modelo de ecuaciones estructurales para determinar las relaciones entre los factores. RESULTADOS: Los factores de predicción del consumo de sustancias ilícitas fueron presentar un bajo control conductual con tendencia a actuar impulsivamente y con agresividad, estar vinculado con pares desviantes y estar expuesto con frecuencia a situaciones familiares de conflicto y violencia y al consumo de sustancias ilícitas y alcohol en el hogar. El modelo de ecuaciones estructurales indicó que el consumo de estas sustancias forma parte de un grupo de trastornos de ajuste conductual, determinado directamente por la vinculación con pares desviantes y por una mayor prevalencia de trastornos socioafectivos, e indirectamente por las relaciones familiares disfuncionales. CONCLUSIONES: Se confirmaron algunas implicaciones de los modelos teóricos propuestos para explicar el consumo de drogas. Estos elementos empíricamente sustentados pueden contribuir al diseño de programas preventivos, principalmente de tipos selectivo e indicado.
OBJECTIVES: To identify psychosocial risk factors for substance abuse among Mexican students and to offer elements for the design of prevention programs. METHODS: A cross-sectional, nonexperimental study of a sample of 516 high school students in six of Mexico's most important cities. From April-June 2005, a customized version of the Drug Use Screening Inventory (revised) (DUSI-R) was administered. The analysis comprised eight factors: alcohol and drug abuse, affective disorders, poor self-control, poor school adjustment, low social competence, dysfunctional family relationships, social isolation, and being part of a detrimental social network (whose members take drugs and have antisocial attitudes). Factors predictive for illicit drug use were found by logistical regression, and a structural equation model was designed to determine the relationships among the factors. RESULTS: The factors that predicted substance abuse were poor self-control with a tendency to act impulsively and aggressively; associating with troublemakers; and being frequently exposed to family conflicts, violence, and drug and/or alcohol use in the home. The structural equation model indicated that substance abuse is one of a group of disorders directly determined by associating with detrimental peers, and a higher rate of socioaffective disorders, and indirectly, by dysfunctional family relationships. CONCLUSIONS: Some of the suggestions made by theoretical models to explain substance abuse were confirmed. These empirically-supported elements can contribute to the design of prevention programs, especially those that are selective and recommended.
Summary The need of cost-effective drug abuse prevention programs has derived in a growing interest to develop scientific based alternatives. On this context, this study forms part of a project for the design and evaluation of a theoretical and empirically sustained intervention for illicit drug abuse prevention among Mexican junior high school students. Starting with the revision and assessment of different theoretical models that could be adapted to the conditions of the institutional context wherein the intervention will be developed, the Azjen and Fishbein’s Theory of Planned Behavior was chosen. This theory includes proximal cognitive and attitude factors directly related to the initiation of drug use. In accordance with it, the experimental use of substances is a result of the intention of consuming them, which, in turn, depends on three elements: a) the attitude toward the drug use, b) the normative beliefs on this matter (subjective norm) and c) the perceived behavioral control regarding drug use or, in turn, confronting social pressure. In a first instance, several items were developed adapting the constructs of the Theory of Planned Behavior to the target population’s characteristics. On this base, the reliability and validity of a self-applied questionnaire for the measurement of the variables of the model was proved. In this work are reported the findings of the evaluation of Theory of Planned Behavior’s potential to predict both behavioral intention of using illicit drugs and consumption of substances among Mexican high school students, in order to set a precedent to apply the model later on in the design and evaluation of a preventive intervention directed to such population. Method: The study was carried on with an ex post facto, correlational design, and with a non-probabilistic sample of 1,019 subjects. Sample. The sample size was estimated considering the possibility of selecting a subsample of drug users and comparison subjects for a post-stratified analysis, assuring a statistical power of 80% and adequate sensibility and stability. Therefore, this work includes the performed analyses with a sample of 75 drug users and 75 non users, paired by gender, age, school grade and occupation. Instrument. The instrument was a self-applied questionnaire specially developed for the study, according to information obtained in previous focal groups interviews with high school students. The questionnaire showed a global realiability of 0.9154 and between 0.62 and 0.94 in each one of its scales, which included: behavioral beliefs (0.9121), attributed value to behavioral beliefs (0.7964), normative beliefs (0.6480), subject’s disposition to adjust to normative expectations (0.8564), descriptive norm (0.6254), drug use opportunities (0.8129) and perceived behavioral control coping with such opportunity situations (0.9442). A factorial analysis of principal components yielded 16 factors of at least three items each, with factorial weights higher than 0.4, and closely attached to Theory of Planned Behavior’s variables, with an explained variance of 59%. Analysis. Previous to data analysis, normality tests (Kolmogorov- Smirnov) were performed, indicating the necessity to apply nonparametric tests of differences and to transform the data to be adapted to the requirements of later parametric analyses. A correlation analysis was carried out to prove the association between behavioral intention and drug use, as well as between the different components of the Theory of Planned Behavior. Finally, linear and logistic regression analyses were conducted to determine the explicative potential of the model and the predictive weight of each variable on the model with regard to the behavioral intention and the consumption of drugs. Findings: According to the Mann-Whitney test, compared with students who had not used drugs, subjects that used them at least once in their life showed more favorable attitudes toward consumption (median= 6.9 vs. 3.9, z=-5.22, p=0.000), perceived more social tolerance (median=3.8 vs. 3.5, z=-2.27, p=0.023), were more willing to give in to social pressure for using substances (median=2.0 vs. 1.0, z=-5.598, p=0.000), perceived a higher number of users among their significant others, and less negative consequences Salud Mental, Vol. 30, No. 1, enero-febrero 2007 69 of drug use in themselves (median=16.3 vs. 7.1, z=-4.246, p=0.000), and felt less capable of behavioral control when coping with opportunities for consumption, which, in turn, are more frequent in their case (median=5.7 vs 1.8, z=-6.76, p=0.000). The correlation between the intention and the behavior of drug use (r=0.41, p<0.000) was allocated inside the range reported in other populations. Drug use intention correlated with attitude toward drug use at r=0.45 (p=0.000), with subjective norm, including additional components at r=0.48 (p=0.000), and with perceived behavioral control at r=0.59 (p=0.000). Drug use correlated with attitude at r=0.51 (p=0.000), with subjective norm at r=0.28 (p=0.001), and with perceived behavioral control at r=0.37 (p=0.000). Linear regression analysis yielded that the model explained 34% of the variance of drug use intention, which increased to 38% when adding personal and descriptive norm elements to the subjective norm construct. Behavioral control (measured on the basis of the product of exposition to drug use facilitating situations punctuations by perceived behavioral control to cope with these situations punctuations) was identified as the best predictor of drug use intention (B=0.32, p=0.001), followed by attitude toward drug use (B=0.24, p=0.004) and subjective norm, which originally showed a non-significant effect but increased its predictive weight when additional elements were added (B=0.24, p=0.004). According to the logistic regression analysis, behavioral control is also the best predictor of illicit drug use on the model (odds ratio= 1.42, p<0.000). On the contrary, subjective norm (including personal and descriptive norm) and attitude (odds ratio=1.144, p=0.06) were not significant predictors of drug use. Discussion: In general, this findings indicate that the Theory of Planned Behavior showed an acceptable predictive capacity (similar to that found in other populations), and can be taken as a valid theoretical ground to develop a preventive intervention directed to Mexican students of high school education. As is the case with other populations, the variable in the Planned Behavior Theory with more predictive weight was perceived behavioral control, followed by attitude to drug use and, in third place, by subjective norm. Despite it could be supposed that subjective norm would have a higher predictive weight in Mexican teenagers, findings probably reflected idiocentric and individualistic tendencies reported in other studies. Results also point out to the convenience of including it in the program of intervention informative components to produce an awareness effect and an impact in the intention of using drugs. Still, they indicate above all, the need to integrate components directed to the development and reinforcement of behavioral control abilities that have an effect in the use of drugs itself. Specifically, it is considered the convenience of including components for the development of group pressure resistance abilities and assertive communication, appropriate to the contexts in which young people face drug abuse risk situations.