انگیزش پیش بینی مشکلات مربوط به مصرف الکل و رضایت از زندگی برای تغییر در میان دانشجویان موظف

The present study investigated the role specific types of alcohol-related problems and life satisfaction play in predicting motivation to change alcohol use. Participants were 548 college students mandated to complete a brief intervention following an alcohol-related policy violation. Using hierarchical multiple regression, we tested for the presence of interaction and quadratic effects on baseline data collected prior to the intervention. A significant interaction indicated that the relationship between a respondent's personal consequences and his/her motivation to change differs depending upon the level of concurrent social consequences. Additionally quadratic effects for abuse/dependence symptoms and life satisfaction were found. The quadratic probes suggest that abuse/dependence symptoms and poor life satisfaction are both positively associated with motivation to change for a majority of the sample; however, the nature of these relationships changes for participants with more extreme scores. Results support the utility of using a multidimensional measure of alcohol related problems and assessing non-linear relationships when assessing predictors of motivation to change. The results also suggest that the best strategies for increasing motivation may vary depending on the types of alcohol-related problems and level of life satisfaction the student is experiencing and highlight potential directions for future research.

The majority of college students (64%) report consuming alcohol in the past month and nearly half (44%) report a binge episode during that time (Substance Abuse and Mental Health Services Administration, 2009). Among college students who drink regularly, nearly half (47%) report experiencing five or more alcohol-related problems in the past year (Wechsler, Davenport, Dowdall, Moeykens, & Castillo, 1994). Research has focused on which factors lead to motivation to decrease alcohol consumption among college students, so that such factors can be incorporated into intervention efforts. Research on motivation to change has been influenced by the transtheoretical model (TTM), a theory introduced to explain how individuals progress toward behavior change (Prochaska and Diclemente, 1982 and Prochaska et al., 1992). The TTM posits that motivation to change is an important element of change; motivation is predictive of outcome, and different processes of change are hypothesized to be more appropriate or effective depending on the level of motivation. Motivation to change is hypothesized to increase when the perceived costs of a behavior outweigh the benefits. Several studies have applied the TTM, and more specifically motivation to change, to college student drinking. Studies focusing on predictors of motivation to change have produced mixed results. For example, one study suggests that light drinkers who have experienced few problems report greater motivation to change (Barnett, Goldstein, Murphy, Colby, & Monti, 2006). However, a second study found that mandated students who experience more alcohol-related problems are more motivated to change their level of alcohol consumption (Shealy, Murphy, Borsari, & Correia, 2007); that study also indicated that motivation to change was related to low life satisfaction. Relatedly, life satisfaction has shown a consistent, negative relationship with alcohol-related problems (Molnar et al., 2009 and Murphy et al., 2005). These latter findings are consistent with the TTM's assertion that motivation to change increases as the costs of alcohol use increase, with costs operationalized in these specific studies as increased negative alcohol-related consequences and decreased life satisfaction. The current study sought to further examine the relationship between alcohol-related problems, life satisfaction, and motivation to change patterns of alcohol use by replicating and extending the methodology used in Shealy et al. (2007). Two significant improvements have been implemented. First, Shealy et al. used single-factor measures to assess alcohol-related problems. However, several recent factor analytic studies using college student samples have shown that alcohol-related problems can be categorized into a number of dimensions (e.g., Maddock et al., 2001, Martens et al., 2007 and Read et al., 2006). For example, the Rutgers Alcohol Problem Index, a commonly used measure of alcohol problems among college students, consists of three subscales: abuse/dependence symptoms, personal consequences, and social consequences (Martens, Neighbors, Dams-O'Connor, Lee, & Larimer, 2007). In addition, research suggests that college students do not perceive various alcohol-related problems to be equally aversive and that some outcomes labeled as problems by researchers may be perceived as neutral or even positive by college students (Mallett et al., 2008 and Mallett et al., 2006). Mallett et al. (2008) suggest that a student's perception of an alcohol-related problem likely influences the relationship between drinking outcomes and motivation to change. Stated more generally, the relationships between alcohol-related problems and motivation to change patterns of alcohol consumption may vary across types or categories of consequences. Indeed, a study of adults enrolled in treatment for alcohol use disorders reported that motivation to change was positively related to social and interpersonal consequences but inversely related to physical consequences (DiClemente, Doyle, & Donovan, 2009). The current study will explore similar relationships in a college student sample by using a multidimensional model of alcohol-related problems. Further, whereas the Shealy et al. (2007) study investigated linear bivariate relationships among alcohol-related problems, life satisfaction, and motivation to change, the current study used a significantly larger sample than Shealy et al. (2007), which allowed for a more detailed analysis of the relationships among the variables. More specifically, interactions among alcohol-related problems and life satisfaction were probed to identify and describe moderation, and both linear and quadratic relationships were tested and described. Based on previous studies, we hypothesized that alcohol-related problems would be positively related to motivation to change, and that life satisfaction would be negatively related to motivation to change. The extant empirical literature does not allow for specific hypotheses regarding interactions and the potential for linear versus non-linear relationships.

3. Results 3.1. Descriptive statistics Participants reported an average of five binge episodes over the past month and consuming 16 drinks per week. For abuse/dependence, personal, and social consequences on the RAPI, participants reported an average of one problem in each category for an average of three alcohol-related problems in the past-month. Descriptive statistics among alcohol-related problems, life satisfaction and motivation to change are presented in Table 1. All variables were significantly correlated with each other and in the direction hypothesized. Bivariate correlations are presented in Table 2. Alcohol-related problems were positively correlated with each other (r's ranging from .43 to .45) and to motivation to change (r's ranging from .17 to .25) and inversely correlated with life satisfaction (r's ranging from − .28 to − .30). Life satisfaction was inversely correlated with motivation to change (− .20). Table 1. Descriptive statistics for primary study variables. Mean Std. dev. Min. Max. Skewness Kurtosis Social 0.96 1.46 0.00 13.50 2.65 12.37 Personal 1.30 1.78 0.00 9.50 1.88 3.78 Abuse 1.40 2.26 0.00 13.00 2.31 5.87 Quality of life 29.34 4.44 9.00 35.00 − 1.25 2.49 Motivation 6.33 6.87 − 12.00 27.00 − 0.61 0.38 Table options Table 2. Descriptive statistics and Pearson correlations. Variable 1 2 3 4 1. Abuse/dependence symptoms 2. Personal .45* 3. Social .43* .44* 4. Life satisfaction − .29* − .28* − .30* 5. Readiness to change .25* .22* .17* − .20* Note: * = p < .01. Table options 3.2. Linear interactions Results of the hierarchical regression analyses are presented in Table 3. The overall model accounted for 14% of the variance in motivation to change, F(14, 533) = 5.95, p < .001. As depicted, there was a significant interaction between social problems and personal problems such that, as social problems increased, there was a weaker relationship between personal problems and motivation to change (t[533] = − 2.01, p = .045, R2block = .01). While this interaction term had only small incremental effect on R2, such indices are incomplete measures of the effect of an interaction on their own, and the magnitude of the change in slope must also be considered ( Champoux & Peters, 1987). Table 3. Unstandardized results from final regression block. B (SE) t p Lower-order terms Intercept 7.729 − .428 18.050 .000 Abuse 1.048 − .242 4.330 .000 Social 0.314 − .315 1.000 .320 Personal 0.552 − .293 1.880 .060 Life satisfaction − 0.302 − .082 − 3.670 .000 Quadratic terms Abuse2 − 0.157 − .050 − 3.170 .002 Social2 − 0.012 − .074 − 0.160 .871 Personal2 − 0.070 − .079 − 0.880 .377 Life satisfaction2 − 0.023 − .009 − 2.520 .012 Interaction terms Abuse by social 0.084 − .093 0.910 .365 Abuse by personal 0.157 − .085 1.860 .064 Abuse by life satisfaction 0.006 − .033 0.170 .868 Social by personal − 0.244 − .122 − 2.010 .045 Social by life satisfaction − 0.043 − .045 − 0.950 .342 Personal by life satisfaction 0.037 − .047 0.800 .424 Table options As shown in Fig. 1, the relationship between a respondent's personal problems and his/her motivation to change differs, depending upon the level of concurrent social problems. The Johnson–Neyman probe revealed that, for participants reporting below average social problems, personal problems were positively associated with motivation to change. However, the relationship between personal problems and motivation to change weakens as social problems increase, eventually becoming non-significant for participants at or above mean levels of social problems (cut-point = − .10; 53% of participants below cut-point). Specifically, social problem scores at the cut-point were associated with a 27% weaker slope of personal problems on motivation than social problem scores at the bottom of the observed spectrum (i.e., a .86-unit difference on the social problem subscale). Full-size image (13 K) Fig. 1. Strength of the relationship between personal problems and motivation to change, across levels of social problems. Dotted lines represent the non-simultaneous 95% confidence bounds for the slope of personal problems, and the darkened line represents the region of social problems where the slope of personal problems is statistically significant. Figure options 3.3. Quadratic effects Regression analyses further revealed significant quadratic effects (R2block = .03) for abuse/dependence symptoms (t[533] = − 3.18, p = .01) and for life satisfaction (t[533] = − 2.52, p = .01). Both of the coefficients for these predictors were negative, indicating that an inverted-U shape characterizes their effects. Results from the probes of abuse and life satisfaction are depicted in Fig. 2 and Fig. 3, respectively. Full-size image (42 K) Fig. 2. Predicted motivation to change (Panel A) and simple slope of abuse/dependence symptoms (Panel B) by levels of reported abuse/dependence symptoms. All other covariates are controlled at their means. Note that dotted lines in Panel B represent the non-simultaneous 95% confidence bounds for the slope. Figure options Full-size image (32 K) Fig. 3. Predicted motivation to change (Panel A) and simple slope (Panel B) of Life Satisfaction (LS) by levels of reported LS. All other covariates are controlled at their means. Note that dotted lines in Panel B represent the non-simultaneous 95% confidence bounds for the slope. Figure options There are two regions of the curve where the relationship between abuse/dependence symptoms and motivation to change is significant. On the lower, less pathological end of the distribution, there is a positive association between abuse/dependence symptoms and motivation to change, with the slope being steepest for those with the least pathology. As implied by its negative regression coefficient, this effect weakens as pathology increases, eventually becoming non-significant (lower cut-point = 2.18; 88% of participants below cut-point).1 However, the probe also revealed a small group of individuals at the top of the distribution for whom abuse/dependence symptoms are actually negatively associated with motivation to change (upper cut-point = 6.55; 3% of participants above cut-point). This effect becomes stronger as abuse increases, with individuals at the maximum score of the distribution (i.e., a 4.72-point difference on the RAPI abuse subscale) having a 147% more negative slope than those at the upper cut-point. Results from the probe for life satisfaction revealed a largely similar trend. For people at the top end of the scale (i.e., people with the least pathology), there is a strong, negative association between life satisfaction and motivation to change. However, as life satisfaction diminishes, each additional unit-change on that predictor is associated with a weaker relationship with motivation, eventually reaching non-significance (cut-point = − 3.49; 83% participants above cut-point). From the maximum score to the cut-point (i.e., an 8.5-point difference on the life satisfaction scale), there was a 74% reduction in slope