Psychology of Addictive Behaviors 2015, Vol. 29, No. 3, 627– 632
© 2015 American Psychological Association 0893-164X/15/$12.00 http://dx.doi.org/10.1037/adb0000083
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Coping-Motivated Marijuana Use Correlates With DSM-5 Cannabis Use Disorder and Psychological Distress Among Emerging Adults Ethan Moitra
Paul P. Christopher
Warren Alpert Medical School of Brown University
Warren Alpert Medical School of Brown University and Butler Hospital, Providence, Rhode Island
Bradley J. Anderson
Michael D. Stein
Butler Hospital, Providence, Rhode Island
Warren Alpert Medical School of Brown University and Butler Hospital, Providence, Rhode Island
Compared to other age cohorts, emerging adults, ages 18 –25 years, have the highest rates of marijuana (MJ) use. We examined the relationship of using MJ to cope with negative emotions, relative to using MJ for enhancement or social purposes, to MJ-associated problems and psychological distress among emerging adults. Participants were 288 community-dwelling emerging adults who reported current MJ use as part of a “Health Behaviors” study. Linear and logistic regressions were used to evaluate the adjusted association of coping-motivated MJ use with the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) cannabis use disorder, MJ-related problem severity, depressive symptoms, and perceived stress. After adjusting for other variables in the regression model, using MJ to cope was positively associated with having DSM-5 cannabis use disorder (OR ⫽ 1.85, 95% CI [1.31, 2.62], p ⬍ .01), MJ problem severity (b ⫽ .41, 95% CI [.24, .57], p ⬍ .01), depression (b ⫽ .36, 95% CI [.23, .49], p ⬍ .01), and perceived stress (b ⫽ .37, 95% CI [.22, .51], p ⬍ .01). Using MJ for enhancement purposes or for social reasons was not associated significantly with any of the dependent variables. Using MJ to cope with negative emotions in emerging adults is associated with MJ-related problems and psychological distress. Assessment of MJ use motivation may be clinically important among emerging adults. Keywords: marijuana, DSM-5, motives, coping, emerging adults
MJ use disorder (Caldeira, Arria, O’Grady, Vincent, & Wish, 2008; Caldeira et al., 2009). Reasons for substance use can vary between and within individuals (Cooper, 1994). Common motives are to cope with negative emotions or distress (e.g., “to forget my worries”), to conform (e.g., “because I felt pressure from others who do it”), for enhancement purposes (e.g., “because I like the feeling”), for expansion (e.g., “to expand my awareness”), and for social purposes (e.g., “it’s what I do with friends”). Conformity-motivated use is driven by a desire to reduce social exclusion, enhancement-motivated use is described as being driven by a desire for excitement or joy, expansion-motivated use relates to seeking cognitive or perceptual enhancement of experiences, and social-motivated use seeks to facilitate social cohesion (Simons, Correia, Carey, & Borsari, 1998; Simons, Gaher, Correia, Hansen, & Christopher, 2005). According to the stress-coping model (Wills & Shiffman, 1985), people may also consume substances as a coping response to stress, with the substance being used to engender positive affect and/or decrease an aversive mood. Enhancement, expansion, and social motives are positively associated with MJ use but less related to negative outcomes such as MJ-related problems or psychological distress (BonnMiller, Zvolensky, & Bernstein, 2007; Brodbeck, Matter, Page, & Moggi, 2007). However, individuals with MJ use disorders have higher rates of enhancement-motivated MJ use compared
Evolving social attitudes toward marijuana (MJ) have led to legalization of its use for medical and recreational purposes in some U.S. states. Over the past 30 years, disapproval of MJ use has decreased across birth cohorts (Keyes et al., 2011), with emerging adults (ages 18 –25 years) being most accepting of use. Compared to other age cohorts, emerging adults (Arnett, 2001) also have the highest rates of MJ use, and substance use disorders peak during this period (Substance Abuse and Mental Health Services Administration [SAMHSA], 2013). Indeed, studies have shown that nearly 10% of college-based emerging adults meet criteria for an
This article was published Online First April 27, 2015. Ethan Moitra, Department of Psychiatry and Human Behavior, Warren Alpert Medical School of Brown University; Paul P. Christopher, Department of Psychiatry and Human Behavior, Warren Alpert Medical School of Brown University and Butler Hospital, Providence, Rhode Island; Bradley J. Anderson, General Medicine Research Unit, Butler Hospital; Michael D. Stein, Department of Medicine and Department of Health Services, Policy, and Practice, Warren Alpert Medical School of Brown University and Butler Hospital. This study was funded by NIAAA Grant R01 AA020509. Trial registered at clinicaltrials.gov as NCT01473719. Correspondence concerning this article should be addressed to Ethan Moitra, Brown University, Department of Psychiatry and Human Behavior, Box G-BH, Providence, RI 02912. E-mail: [email protected] 627
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to more casual MJ users (Bonn-Miller & Zvolensky, 2009). Although using MJ to conform is associated with social anxiety symptoms (Buckner, Bonn-Miller, Zvolensky, & Schmidt, 2007), it has been found to negatively correlate with recent MJ use (Bonn-Miller, Zvolensky, & Bernstein, 2007). Although most emerging adults report using MJ primarily for enhancement or social reasons (Lee, Neighbors, & Woods, 2007), those who endorse greater MJ use to cope with distress may represent a subgroup trying to manage more severe mental health problems and, in doing so, may be at risk for MJ-related problems. Emerging adults may be more likely than other adults to use MJ to cope with psychological distress (Buckner, 2013). Using MJ to cope with distress is associated with negative affect, anxious arousal, and depressive symptoms (Beck et al., 2009; Mitchell, Zvolensky, Marshall, Bonn-Miller, & Vujanovic, 2007). Among emerging adults with a history of trauma, coping-motivated use, but not other motives, is associated with posttraumatic stress symptoms (Bonn-Miller, Vujanovic, Feldner, Bernstein, & Zvolensky, 2007). Using MJ to cope with negative emotions is also uniquely associated with emotional dysregulation (Bonn-Miller, Vujanovic, & Zvolensky, 2008) and social anxiety symptoms (Buckner et al., 2007) relative to other motives. Although these studies indicate that emerging adults who use MJ to cope experience psychological distress, they are limited by the exclusion of individuals with current Axis I psychopathology (Bonn-Miller, Vujanovic, et al., 2007) and restriction to college students (Buckner et al., 2007). A more representative sample of emerging adults who use MJ to cope with distress is needed to better understand the relationship among these factors. Coping-motivated MJ use in emerging adults is also associated with more persistent use (Patrick, Schulenberg, O’Malley, Johnston, & Bachman, 2011; Patrick, Schulenberg, O’Malley, Maggs, et al., 2011; Titus, Godley, & White, 2007). Persistent use can lead to MJ-related problems, particularly for individuals who start using earlier in life (Anthony & Petronis, 1995). Among emerging adult MJ users, those who use to cope with distress are at increased risk for MJ-related problems (Buckner, 2013; Lee et al., 2007) and are more likely to meet criteria from the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV; American Psychiatric Association, 2000) for MJ dependence (Bonn-Miller & Zvolensky, 2009). Yet the DSM-IV had inadequate clinical utility in discriminating MJ problem severity among emerging adults (Martin, Chung, Kirisci, & Langenbucher, 2006). To our knowledge, no study has investigated the link between using MJ to cope with distress and cannabis use disorder as defined in the fifth edition of the DSM (DSM-5; American Psychiatric Association, 2013). In this study, we examined the association of motivations for using MJ (social, enhancement, and coping) in emerging adults with four measures of MJ-related problem severity and psychological distress: (a) meeting DSM-5 criteria for cannabis use disorder, (b) MJ-related problem severity, (c) depressive symptomatology, and (d) perceived stress. We hypothesized that coping-motivated use would be more strongly associated with these adverse outcomes than social- or enhancement-motivated use.
Method Participants Participants were recruited for a large study on health behaviors among emerging adults who use MJ or alcohol through advertisements online, in local college newspapers, on public transportation, and on commercial radio in Rhode Island. After a telephone screen, eligible individuals were invited for a compensated ($40) in-person interview and free sexually transmitted infection testing. The study was approved by the Butler Hospital Institutional Review Board. Eligibility criteria included being 18 –25 years old, drinking alcohol and/or using MJ in the past month, being sexually active in the past 6 months, not having suicidal ideation in the past 2 weeks, and living within 30 minutes of the research site. Of the 1,621 individuals screened by phone, 689 were ineligible. The remaining 932 eligible persons were invited for an interview, and 533 were either not interested or did not keep a scheduled baseline appointment. In total, 399 individuals completed baseline interviews, after which 17 persons were found to be ineligible. For the present analysis, we included data only from individuals who reported using MJ in the past 30 days (n ⫽ 288).
Measures Frequency of cigarette smoking. Frequency of cigarette smoking was assessed using an item from the Fagerström Test for Nicotine Dependence (Heatherton, Kozlowski, Frecker, & Fagerström, 1991): “How many cigarettes do you smoke per day?” Marijuana Problem Scale. The Marijuana Problem Scale (MPS; Stephens, Roffman, & Curtin, 2000; Stephens et al., 2004) is a reliable and valid measure (score range 0 – 48) of 19 problems directly related to MJ use, ranging from losing a job to having withdrawal symptoms to having problems in one’s family. Patient Health Questionnaire–9. The Patient Health Questionnaire–9 (PHQ-9; Kroenke, Spitzer, & Williams, 2001) is a validated and reliable nine-item measure (score range 0 –27) of depressive symptoms. Perceived Stress Scale– 4. The Perceived Stress Scale– 4 (PSS-4; Cohen, Kamarck, & Mermelstein, 1983) is a four-item measure (score range 0 –16) that assesses the degree to which individuals perceive their environment and experiences as stressful. Reasons for Marijuana Use. We adapted the Reasons for Drinking measure developed by Cooper, Russell, Skinner, and Windle (1992) for this study to examine MJ use motives. This measure has three subscales: (a) coping (sample item, “Because it helped when you felt depressed or nervous”), (b) enhancement (“Because it’s exciting”), and (c) social (“To be sociable”). The Reasons for Marijuana Use subscales had a possible range of 1– 4, corresponding to never/almost never, sometimes, often, and almost always. In this sample, internal consistency reliabilities were .84, .84, and .73 for the coping, enhancement, and social scales, respectively. Product-moment correlations between the subscales ranged from .45–.47. Structured Interview for the DSM-IV— cannabis abuse and dependence modules. The Structured Interview for the DSM-IV (First, Spitzer, Gibbon, & Williams, 1996) is the most widely used,
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COPING-MOTIVATED MARIJUANA USE IN EMERGING ADULTS
reliable, and well-validated, structured clinical assessment tool for DSM-IV diagnostic criteria. To assess the craving criterion under DSM-5 defined cannabis use disorder, we asked all participants, “In the past 3 months, have you often had cravings or strong desires or urges to use marijuana?” Participants endorsing two or more of the abuse or dependence items, including our additional craving question, met criteria for DSM-5 cannabis use disorder. Severity of cannabis use disorder was coded by number of criteria endorsed: no disorder ⫽ zero or one symptom, mild ⫽ two or three symptoms, moderate ⫽ four or five symptoms, and severe ⫽ six or more symptoms (Hasin et al., 2013). Timeline Follow-Back Measure. The Timeline Follow-Back Measure (TLFB; Sobell & Sobell, 1996) is a semistructured interview that uses a calendar-guided approach (Fals-Stewart, O’Farrell, Freitas, McFarlin, & Rutigliano, 2000) and assesses alcohol and MJ use in the past 30 days.
Data Analysis Descriptive statistics summarize the characteristics of the sample. Our primary focus is on the associations of using MJ for coping, socialization, and enhancement with indicators of MJ use severity and problems. We also examined associations with measures of psychological well-being. Background characteristics included as covariates were age, gender, ethnoracial group, employment status, education, alcohol use frequency (past 30 days), MJ use frequency (past 30 days), and number of cigarettes smoked per day (past 30 days). Associations were estimated in a seemingly unrelated regression framework (Zellner, 1962) using Mplus 5.1 (Muthén & Muthén, 2008). This method assumes error terms are correlated across equations and parameter estimates are more efficient than equation-by-equation estimation. The interpretation of estimated coefficients is identical to single-equation regression models. Prior to analysis, all continuous variables were standardized to zero-mean and unit variance. For the equations with continuous dependent variables (PHQ-9, PSS-4, and MPS), the coefficients reported for continuous factors are fully standardized regression coefficients, and the coefficients for the categorical factors are y-standardized. Associations with meeting criteria for DSM-5 cannabis use disorder are reported as odds ratios. Parameters and inferential statistics were estimated using maximum likelihood with robust standard errors (MLR in Mplus). All abovedescribed covariates and the three motivation-to-use MJ subscales were entered simultaneously in the multivariate models. An indicator variable contrasting non-Latino Whites to all other racial or ethnic identifications was used in analyses.
Results Of the 288 emerging adults who reported MJ use in the past 30 days, mean age was 21.2 (SD ⫽ 2.1) years, 135 (51.7%) were male, and 187 (64.9%) were non-Latino White (see Table 1). On average, participants used alcohol and MJ on 26.7% (SD ⫽ 18.0%) and 52.5% (SD ⫽ 38.1%) of TLFB days, respectively. More than two thirds (70.5%) reported no cigarette smoking in the 30 days prior to baseline. After adjusting for other variables in the model, including using MJ for enhancement and social reasons, using MJ to cope with distress was positively and significantly associated with meeting
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Table 1 Background Characteristics and Descriptive Statistics (n ⫽ 288) M ⫾ SD or n (%) Background characteristics Age (y) Gender (male) Race/ethnicity White (non-Latino) African American Latino Other minority Employed (part- or full-time) Enrolled in school % Days used alcohol (past 90 days) Cigarettes/day None 5 or less 6–10 11–20 21–30 % Days used marijuana (past 90 days) Reasons to use marijuana Coping Socialization Enhancement Psychological and marijuana correlates Patient Health Questionnaire–9 (depression) Perceived Stress Scale–4 Marijuana Problem Scale Cannabis use disorder Mild Moderate Severe
21.2 ⫾ 2.1 135 (51.7) 187 (64.9) 37 (12.8) 36 (12.5) 28 (9.7) 59 (20.5) 170 (59.0) 26.7 ⫾ 18.0 203 (70.5) 41 (14.2) 31 (10.8) 11 (3.8) 2 (0.7) 52.5 ⫾ 38.12 2.23 ⫾ 0.75 2.41 ⫾ 0.72 3.00 ⫾ 0.71 6.58 ⫾ 5.44 5.78 ⫾ 2.82 7.13 ⫾ 6.00 172 (59.7) 81 (28.1) 49 (17.0) 42 (14.6)
DSM-5 diagnostic criteria for cannabis use disorder (OR ⫽ 1.85, 95% CI [1.31, 2.62], p ⬍ .01). As a supplementary analysis, we estimated a parallel ordinal logit regression model in which cannabis use disorder severity was regressed on the reasons to use indices and all covariates described in Table 2; results were consistent with those reported for the dichotomized outcome. Using MJ to cope was associated positively and significantly with cannabis use disorder severity (OR ⫽ 1.59, 95% CI [1.15, 2.19], p ⬍ .05). Neither using for social reasons (OR ⫽ 1.46, 95% CI [0.98, 2.18], p ⬎ .05) nor using for enhancement (OR ⫽ 0.94, 95% CI [0.66, 1.34], p ⬎ .05) was associated significantly with cannabis use disorder severity. Results were the same when analyzing the unique associations of the three reasons for using MJ and cannabis use disorder based on number of criteria endorsed. Using MJ to cope was also significantly associated with MJ problem severity (b ⫽ .41, 95% CI [.24, .57], p ⬍ .01), depressive symptomatology (b ⫽ .36, 95% CI [.23, .49], p ⬍ .01), and perceived stress (b ⫽ .37, 95% CI [.22, .51], p ⬍ .01; see Table 2). These multivariate models estimated the effects of the other reasons for using MJ subscales, revealing that using MJ to socialize or for enhancement purposes was not uniquely associated significantly with any of the dependent variables (see Table 2).
Discussion This study found that among emerging adults who use MJ, use to cope with distress is positively and significantly associated with having a DSM-5 cannabis use disorder. Using MJ for enhancement
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Table 2 Seemingly Unrelated Regression Model Estimating the Adjusted Association of Using Marijuana to Cope, to Socialize, and for Enhancement on Various Measures (n ⫽ 288) Predictor
Cannabis Disorder, ORa [95% CI]
MPS, ba [95% CI]
PHQ-9, ba [95% CI]
PSS-4, ba [95% CI]
Age (y) Male Non-Latino White Employed In school Alcohol use frequency Cigarettes/day Marijuana use frequency Coping Social Enhancement
0.95 [0.69, 1.31] 0.69 [0.38, 1.26] 0.88 [0.49, 1.58] 0.94 [0.55, 1.62] 0.79 [0.42, 1.51] 1.01 [0.72, 1.41] 1.06 [0.74, 1.50] 2.68ⴱ [1.85, 3.87] 1.85ⴱ [1.31, 2.62] 1.27 [0.89, 1.79] 1.19 [0.84, 1.70]
⫺.06 [⫺.18, .06] ⫺.04 [⫺.28, .20] .05 [⫺.20, .30] ⫺.01 [⫺.21, .19] ⫺.13 [⫺.39, .13] .03 [⫺.09, .15] ⫺.00 [⫺.14, .13] .07 [⫺.08, .22] .41ⴱ [.24, .57] .10 [⫺.03, .22] ⫺.02 [⫺.13, .09]
.01 [⫺.12, .14] ⫺.51ⴱ [⫺.73, ⫺.29] .04 [⫺.27, .19] ⫺.20 [⫺.41, ⫺.01] ⫺.06 [⫺.31, .19] ⫺.01 [⫺.13, .11] .11 [⫺.02, 0.24] ⫺.05 [⫺.18, .07] .36ⴱ [.23, .49] ⫺.08 [⫺.20, .05] ⫺.09 [⫺.21, .04]
.04 [⫺.08, .16] ⫺.42ⴱ [⫺.64, ⫺.20] .11 [⫺.13, .35] ⫺.21 [⫺.42, ⫺.06] ⫺.18 [⫺.42, .06] .01 [⫺.11, .13] .08 [⫺.04, .20] ⫺.08 [⫺.21, .06] .37ⴱ [.22, .51] ⫺.14 [⫺.29, .01] ⫺.05 [⫺.18, .09]
Note. MPS ⫽ Marijuana Problem Scale; PHQ-9 ⫽ Patient Health Questionnaire–9; PSS-4 ⫽ Perceived Stress Scale– 4. Reported coefficients for continuous predictor variables are fully standardized; coefficients for categorical predictors are y-standardized. Parameters and standard errors were estimated by maximum likelihood with robust standard errors. ⴱ p ⬍ .01. a
or social purposes did not uniquely account for a significant proportion of variance in this outcome. Moreover, copingmotivated use, but not social- or enhancement-motivated use, is associated with MJ-related problems in this group. Using MJ to cope with negative emotions among emerging adults also appears to be uniquely associated with psychiatric symptoms, as measured by severity of depressive symptoms and degree of perceived stress, consistent with prior research (Mitchell et al., 2007). These data are the first to demonstrate the confluence of cannabis use disorder, MJ-related problems, and psychiatric symptoms in the same sample. In addition, a significant shortcoming of previous work was the exclusion of individuals who met DSM diagnostic criteria for Axis I psychopathology (Bonn-Miller, Vujanovic, et al., 2007; Bonn-Miller et al., 2008; Bonn-Miller & Zvolensky, 2009), a meaningful omission given the concern for mental health issues in these individuals. The acceptability of MJ use is growing in emerging adults (Keyes et al., 2011), a high-risk group for substance use disorders (SAMHSA, 2013). Although prior studies have shown an association between coping-motivated MJ use and a variety of negative psychological factors (e.g., Mitchell et al., 2007), little research has compared the relationship of coping-motivated use, relative to social- and enhancement-based use, to MJ-related problems and psychological variables. These are also the first results linking using MJ to cope with psychological distress to the newly defined DSM-5 cannabis use disorder. This new diagnostic category represents an important streamlining of the DSM’s cannabis abuse and dependence diagnoses while incorporating a severity dimension. This new approach is particularly relevant to clinicians working with emerging adults, because the DSM-IV classification system poorly quantified severity of use in this age group (Martin et al., 2006). This study had limitations. First, our primary measure of MJ use motives was adapted from an alcohol scale. Moreover, we did not measure conformity- or expansion-motivated use; these would be important to include in future research. Second, although copingmotivated use was significantly associated with negative psychological variables, our estimated standardized effect sizes suggest
that coping-motivated use might not be the only factor associated with these outcomes. Third, the sample was limited to emerging adults who had past-month MJ use, were not seeking treatment, and were sexually active. Although the sample had the strengths of not excluding those with Axis I psychopathology, being ethnically/ racially diverse, being nearly half female, and including a substantial number of emerging adults not currently in school (41%), it was not an epidemiological sample. Furthermore, ⬎ 50% of potential participants declined to participate in the study. Fourth, we did not use a diagnostic measure to assess the presence of major depressive disorder. Fifth, MJ-induced anxiety is one of the most commonly reported acute symptoms of MJ use (Crippa et al., 2009). Thus, it is possible that self-reported use of MJ to cope with distress is confounded by MJ-triggered symptoms. Finally, given the cross-sectional nature of the data, we were unable to examine the temporal relationship between coping-motivated use and psychological distress. Still, our findings suggest that assessment of use of MJ to manage psychological distress may be clinically important and, if found, signal the importance of a broad and careful mental health assessment. These results raise the question about how coping-motivated MJ use might improve or worsen one’s well-being. Although MJ may be perceived as beneficial in ameliorating symptoms of emotional distress, long-term MJ use for these purposes has been associated with deleterious consequences (Patrick, Schulenberg, O’Malley, Johnston, et al., 2011). More longitudinal research will be needed to examine if, despite being used with the intention of mitigating distress, coping-motivated use may actually worsen psychological health.
Conclusions MJ use is becoming more socially acceptable and common in emerging adults. These results help clinicians identify MJ-using individuals who are likely to also have psychological distress symptoms. It appears that there is an important subset of emerging adults who use MJ for coping purposes, and these individuals are at risk for a variety of MJ-related problems. Clinicians working
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with patients who use MJ to cope with negative emotions face the challenge of confronting misconceptions about the perceived benefit of using MJ to “treat” distress. If MJ users continue to be reluctant to engage in drug counseling or to reduce use, despite having substance-related problems, clinicians must become more open to providing treatment such as alternative coping strategies for what these users might be more motivated to change, namely, their symptoms of psychological distress.
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Substance Abuse and Mental Health Services Administration (SAMHSA). (2013). Results from the 2012 National Survey on Drug Use and Health: Summary of National Findings. Rockville, MD: Author. Retrieved from http://www.samhsa.gov/data/NSDUH/2012SummNatFindDetTables/ Simons, J. S., Correia, C. J., Carey, K. B., & Borsari, B. E. (1998). Validating a five-factor marijuana motives measure: Relations with use, problems, and alcohol motives. Journal of Counseling Psychology, 45, 265–273. http://dx.doi.org/10.1037/0022-0167.45.3.265 Simons, J. S., Gaher, R. M., Correia, C. J., Hansen, C. L., & Christopher, M. S. (2005). An affective-motivational model of marijuana and alcohol problems among college students. Psychology of Addictive Behaviors, 19, 326 –334. http://dx.doi.org/10.1037/0893-164X.19.3.326 Sobell, L. C., & Sobell, M. B. (1996). Timeline Followback user’s guide: A calendar method for assessing alcohol and drug use. Toronto, Ontario, Canada: Addiction Research Foundation. Stephens, R. S., Roffman, R. A., & Curtin, L. (2000). Comparison of extended versus brief treatments for marijuana use. Journal of Consulting and Clinical Psychology, 68, 898 –908. http://dx.doi.org/10.1037/ 0022-006X.68.5.898
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Received December 8, 2014 Revision received March 2, 2015 Accepted March 9, 2015 䡲
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Coping-Motivated Marijuana Use Correlates With DSM-5 Cannabis Use Disorder and Psychological Distress Among Emerging Adults Ethan Moitra
Paul P. Christopher
Warren Alpert Medical School of Brown University
Warren Alpert Medical School of Brown University and Butler Hospital, Providence, Rhode Island
Bradley J. Anderson
Michael D. Stein
Butler Hospital, Providence, Rhode Island
Warren Alpert Medical School of Brown University and Butler Hospital, Providence, Rhode Island
Compared to other age cohorts, emerging adults, ages 18 –25 years, have the highest rates of marijuana (MJ) use. We examined the relationship of using MJ to cope with negative emotions, relative to using MJ for enhancement or social purposes, to MJ-associated problems and psychological distress among emerging adults. Participants were 288 community-dwelling emerging adults who reported current MJ use as part of a “Health Behaviors” study. Linear and logistic regressions were used to evaluate the adjusted association of coping-motivated MJ use with the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) cannabis use disorder, MJ-related problem severity, depressive symptoms, and perceived stress. After adjusting for other variables in the regression model, using MJ to cope was positively associated with having DSM-5 cannabis use disorder (OR ⫽ 1.85, 95% CI [1.31, 2.62], p ⬍ .01), MJ problem severity (b ⫽ .41, 95% CI [.24, .57], p ⬍ .01), depression (b ⫽ .36, 95% CI [.23, .49], p ⬍ .01), and perceived stress (b ⫽ .37, 95% CI [.22, .51], p ⬍ .01). Using MJ for enhancement purposes or for social reasons was not associated significantly with any of the dependent variables. Using MJ to cope with negative emotions in emerging adults is associated with MJ-related problems and psychological distress. Assessment of MJ use motivation may be clinically important among emerging adults. Keywords: marijuana, DSM-5, motives, coping, emerging adults
MJ use disorder (Caldeira, Arria, O’Grady, Vincent, & Wish, 2008; Caldeira et al., 2009). Reasons for substance use can vary between and within individuals (Cooper, 1994). Common motives are to cope with negative emotions or distress (e.g., “to forget my worries”), to conform (e.g., “because I felt pressure from others who do it”), for enhancement purposes (e.g., “because I like the feeling”), for expansion (e.g., “to expand my awareness”), and for social purposes (e.g., “it’s what I do with friends”). Conformity-motivated use is driven by a desire to reduce social exclusion, enhancement-motivated use is described as being driven by a desire for excitement or joy, expansion-motivated use relates to seeking cognitive or perceptual enhancement of experiences, and social-motivated use seeks to facilitate social cohesion (Simons, Correia, Carey, & Borsari, 1998; Simons, Gaher, Correia, Hansen, & Christopher, 2005). According to the stress-coping model (Wills & Shiffman, 1985), people may also consume substances as a coping response to stress, with the substance being used to engender positive affect and/or decrease an aversive mood. Enhancement, expansion, and social motives are positively associated with MJ use but less related to negative outcomes such as MJ-related problems or psychological distress (BonnMiller, Zvolensky, & Bernstein, 2007; Brodbeck, Matter, Page, & Moggi, 2007). However, individuals with MJ use disorders have higher rates of enhancement-motivated MJ use compared
Evolving social attitudes toward marijuana (MJ) have led to legalization of its use for medical and recreational purposes in some U.S. states. Over the past 30 years, disapproval of MJ use has decreased across birth cohorts (Keyes et al., 2011), with emerging adults (ages 18 –25 years) being most accepting of use. Compared to other age cohorts, emerging adults (Arnett, 2001) also have the highest rates of MJ use, and substance use disorders peak during this period (Substance Abuse and Mental Health Services Administration [SAMHSA], 2013). Indeed, studies have shown that nearly 10% of college-based emerging adults meet criteria for an
This article was published Online First April 27, 2015. Ethan Moitra, Department of Psychiatry and Human Behavior, Warren Alpert Medical School of Brown University; Paul P. Christopher, Department of Psychiatry and Human Behavior, Warren Alpert Medical School of Brown University and Butler Hospital, Providence, Rhode Island; Bradley J. Anderson, General Medicine Research Unit, Butler Hospital; Michael D. Stein, Department of Medicine and Department of Health Services, Policy, and Practice, Warren Alpert Medical School of Brown University and Butler Hospital. This study was funded by NIAAA Grant R01 AA020509. Trial registered at clinicaltrials.gov as NCT01473719. Correspondence concerning this article should be addressed to Ethan Moitra, Brown University, Department of Psychiatry and Human Behavior, Box G-BH, Providence, RI 02912. E-mail: [email protected] 627
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to more casual MJ users (Bonn-Miller & Zvolensky, 2009). Although using MJ to conform is associated with social anxiety symptoms (Buckner, Bonn-Miller, Zvolensky, & Schmidt, 2007), it has been found to negatively correlate with recent MJ use (Bonn-Miller, Zvolensky, & Bernstein, 2007). Although most emerging adults report using MJ primarily for enhancement or social reasons (Lee, Neighbors, & Woods, 2007), those who endorse greater MJ use to cope with distress may represent a subgroup trying to manage more severe mental health problems and, in doing so, may be at risk for MJ-related problems. Emerging adults may be more likely than other adults to use MJ to cope with psychological distress (Buckner, 2013). Using MJ to cope with distress is associated with negative affect, anxious arousal, and depressive symptoms (Beck et al., 2009; Mitchell, Zvolensky, Marshall, Bonn-Miller, & Vujanovic, 2007). Among emerging adults with a history of trauma, coping-motivated use, but not other motives, is associated with posttraumatic stress symptoms (Bonn-Miller, Vujanovic, Feldner, Bernstein, & Zvolensky, 2007). Using MJ to cope with negative emotions is also uniquely associated with emotional dysregulation (Bonn-Miller, Vujanovic, & Zvolensky, 2008) and social anxiety symptoms (Buckner et al., 2007) relative to other motives. Although these studies indicate that emerging adults who use MJ to cope experience psychological distress, they are limited by the exclusion of individuals with current Axis I psychopathology (Bonn-Miller, Vujanovic, et al., 2007) and restriction to college students (Buckner et al., 2007). A more representative sample of emerging adults who use MJ to cope with distress is needed to better understand the relationship among these factors. Coping-motivated MJ use in emerging adults is also associated with more persistent use (Patrick, Schulenberg, O’Malley, Johnston, & Bachman, 2011; Patrick, Schulenberg, O’Malley, Maggs, et al., 2011; Titus, Godley, & White, 2007). Persistent use can lead to MJ-related problems, particularly for individuals who start using earlier in life (Anthony & Petronis, 1995). Among emerging adult MJ users, those who use to cope with distress are at increased risk for MJ-related problems (Buckner, 2013; Lee et al., 2007) and are more likely to meet criteria from the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV; American Psychiatric Association, 2000) for MJ dependence (Bonn-Miller & Zvolensky, 2009). Yet the DSM-IV had inadequate clinical utility in discriminating MJ problem severity among emerging adults (Martin, Chung, Kirisci, & Langenbucher, 2006). To our knowledge, no study has investigated the link between using MJ to cope with distress and cannabis use disorder as defined in the fifth edition of the DSM (DSM-5; American Psychiatric Association, 2013). In this study, we examined the association of motivations for using MJ (social, enhancement, and coping) in emerging adults with four measures of MJ-related problem severity and psychological distress: (a) meeting DSM-5 criteria for cannabis use disorder, (b) MJ-related problem severity, (c) depressive symptomatology, and (d) perceived stress. We hypothesized that coping-motivated use would be more strongly associated with these adverse outcomes than social- or enhancement-motivated use.
Method Participants Participants were recruited for a large study on health behaviors among emerging adults who use MJ or alcohol through advertisements online, in local college newspapers, on public transportation, and on commercial radio in Rhode Island. After a telephone screen, eligible individuals were invited for a compensated ($40) in-person interview and free sexually transmitted infection testing. The study was approved by the Butler Hospital Institutional Review Board. Eligibility criteria included being 18 –25 years old, drinking alcohol and/or using MJ in the past month, being sexually active in the past 6 months, not having suicidal ideation in the past 2 weeks, and living within 30 minutes of the research site. Of the 1,621 individuals screened by phone, 689 were ineligible. The remaining 932 eligible persons were invited for an interview, and 533 were either not interested or did not keep a scheduled baseline appointment. In total, 399 individuals completed baseline interviews, after which 17 persons were found to be ineligible. For the present analysis, we included data only from individuals who reported using MJ in the past 30 days (n ⫽ 288).
Measures Frequency of cigarette smoking. Frequency of cigarette smoking was assessed using an item from the Fagerström Test for Nicotine Dependence (Heatherton, Kozlowski, Frecker, & Fagerström, 1991): “How many cigarettes do you smoke per day?” Marijuana Problem Scale. The Marijuana Problem Scale (MPS; Stephens, Roffman, & Curtin, 2000; Stephens et al., 2004) is a reliable and valid measure (score range 0 – 48) of 19 problems directly related to MJ use, ranging from losing a job to having withdrawal symptoms to having problems in one’s family. Patient Health Questionnaire–9. The Patient Health Questionnaire–9 (PHQ-9; Kroenke, Spitzer, & Williams, 2001) is a validated and reliable nine-item measure (score range 0 –27) of depressive symptoms. Perceived Stress Scale– 4. The Perceived Stress Scale– 4 (PSS-4; Cohen, Kamarck, & Mermelstein, 1983) is a four-item measure (score range 0 –16) that assesses the degree to which individuals perceive their environment and experiences as stressful. Reasons for Marijuana Use. We adapted the Reasons for Drinking measure developed by Cooper, Russell, Skinner, and Windle (1992) for this study to examine MJ use motives. This measure has three subscales: (a) coping (sample item, “Because it helped when you felt depressed or nervous”), (b) enhancement (“Because it’s exciting”), and (c) social (“To be sociable”). The Reasons for Marijuana Use subscales had a possible range of 1– 4, corresponding to never/almost never, sometimes, often, and almost always. In this sample, internal consistency reliabilities were .84, .84, and .73 for the coping, enhancement, and social scales, respectively. Product-moment correlations between the subscales ranged from .45–.47. Structured Interview for the DSM-IV— cannabis abuse and dependence modules. The Structured Interview for the DSM-IV (First, Spitzer, Gibbon, & Williams, 1996) is the most widely used,
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COPING-MOTIVATED MARIJUANA USE IN EMERGING ADULTS
reliable, and well-validated, structured clinical assessment tool for DSM-IV diagnostic criteria. To assess the craving criterion under DSM-5 defined cannabis use disorder, we asked all participants, “In the past 3 months, have you often had cravings or strong desires or urges to use marijuana?” Participants endorsing two or more of the abuse or dependence items, including our additional craving question, met criteria for DSM-5 cannabis use disorder. Severity of cannabis use disorder was coded by number of criteria endorsed: no disorder ⫽ zero or one symptom, mild ⫽ two or three symptoms, moderate ⫽ four or five symptoms, and severe ⫽ six or more symptoms (Hasin et al., 2013). Timeline Follow-Back Measure. The Timeline Follow-Back Measure (TLFB; Sobell & Sobell, 1996) is a semistructured interview that uses a calendar-guided approach (Fals-Stewart, O’Farrell, Freitas, McFarlin, & Rutigliano, 2000) and assesses alcohol and MJ use in the past 30 days.
Data Analysis Descriptive statistics summarize the characteristics of the sample. Our primary focus is on the associations of using MJ for coping, socialization, and enhancement with indicators of MJ use severity and problems. We also examined associations with measures of psychological well-being. Background characteristics included as covariates were age, gender, ethnoracial group, employment status, education, alcohol use frequency (past 30 days), MJ use frequency (past 30 days), and number of cigarettes smoked per day (past 30 days). Associations were estimated in a seemingly unrelated regression framework (Zellner, 1962) using Mplus 5.1 (Muthén & Muthén, 2008). This method assumes error terms are correlated across equations and parameter estimates are more efficient than equation-by-equation estimation. The interpretation of estimated coefficients is identical to single-equation regression models. Prior to analysis, all continuous variables were standardized to zero-mean and unit variance. For the equations with continuous dependent variables (PHQ-9, PSS-4, and MPS), the coefficients reported for continuous factors are fully standardized regression coefficients, and the coefficients for the categorical factors are y-standardized. Associations with meeting criteria for DSM-5 cannabis use disorder are reported as odds ratios. Parameters and inferential statistics were estimated using maximum likelihood with robust standard errors (MLR in Mplus). All abovedescribed covariates and the three motivation-to-use MJ subscales were entered simultaneously in the multivariate models. An indicator variable contrasting non-Latino Whites to all other racial or ethnic identifications was used in analyses.
Results Of the 288 emerging adults who reported MJ use in the past 30 days, mean age was 21.2 (SD ⫽ 2.1) years, 135 (51.7%) were male, and 187 (64.9%) were non-Latino White (see Table 1). On average, participants used alcohol and MJ on 26.7% (SD ⫽ 18.0%) and 52.5% (SD ⫽ 38.1%) of TLFB days, respectively. More than two thirds (70.5%) reported no cigarette smoking in the 30 days prior to baseline. After adjusting for other variables in the model, including using MJ for enhancement and social reasons, using MJ to cope with distress was positively and significantly associated with meeting
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Table 1 Background Characteristics and Descriptive Statistics (n ⫽ 288) M ⫾ SD or n (%) Background characteristics Age (y) Gender (male) Race/ethnicity White (non-Latino) African American Latino Other minority Employed (part- or full-time) Enrolled in school % Days used alcohol (past 90 days) Cigarettes/day None 5 or less 6–10 11–20 21–30 % Days used marijuana (past 90 days) Reasons to use marijuana Coping Socialization Enhancement Psychological and marijuana correlates Patient Health Questionnaire–9 (depression) Perceived Stress Scale–4 Marijuana Problem Scale Cannabis use disorder Mild Moderate Severe
21.2 ⫾ 2.1 135 (51.7) 187 (64.9) 37 (12.8) 36 (12.5) 28 (9.7) 59 (20.5) 170 (59.0) 26.7 ⫾ 18.0 203 (70.5) 41 (14.2) 31 (10.8) 11 (3.8) 2 (0.7) 52.5 ⫾ 38.12 2.23 ⫾ 0.75 2.41 ⫾ 0.72 3.00 ⫾ 0.71 6.58 ⫾ 5.44 5.78 ⫾ 2.82 7.13 ⫾ 6.00 172 (59.7) 81 (28.1) 49 (17.0) 42 (14.6)
DSM-5 diagnostic criteria for cannabis use disorder (OR ⫽ 1.85, 95% CI [1.31, 2.62], p ⬍ .01). As a supplementary analysis, we estimated a parallel ordinal logit regression model in which cannabis use disorder severity was regressed on the reasons to use indices and all covariates described in Table 2; results were consistent with those reported for the dichotomized outcome. Using MJ to cope was associated positively and significantly with cannabis use disorder severity (OR ⫽ 1.59, 95% CI [1.15, 2.19], p ⬍ .05). Neither using for social reasons (OR ⫽ 1.46, 95% CI [0.98, 2.18], p ⬎ .05) nor using for enhancement (OR ⫽ 0.94, 95% CI [0.66, 1.34], p ⬎ .05) was associated significantly with cannabis use disorder severity. Results were the same when analyzing the unique associations of the three reasons for using MJ and cannabis use disorder based on number of criteria endorsed. Using MJ to cope was also significantly associated with MJ problem severity (b ⫽ .41, 95% CI [.24, .57], p ⬍ .01), depressive symptomatology (b ⫽ .36, 95% CI [.23, .49], p ⬍ .01), and perceived stress (b ⫽ .37, 95% CI [.22, .51], p ⬍ .01; see Table 2). These multivariate models estimated the effects of the other reasons for using MJ subscales, revealing that using MJ to socialize or for enhancement purposes was not uniquely associated significantly with any of the dependent variables (see Table 2).
Discussion This study found that among emerging adults who use MJ, use to cope with distress is positively and significantly associated with having a DSM-5 cannabis use disorder. Using MJ for enhancement
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Table 2 Seemingly Unrelated Regression Model Estimating the Adjusted Association of Using Marijuana to Cope, to Socialize, and for Enhancement on Various Measures (n ⫽ 288) Predictor
Cannabis Disorder, ORa [95% CI]
MPS, ba [95% CI]
PHQ-9, ba [95% CI]
PSS-4, ba [95% CI]
Age (y) Male Non-Latino White Employed In school Alcohol use frequency Cigarettes/day Marijuana use frequency Coping Social Enhancement
0.95 [0.69, 1.31] 0.69 [0.38, 1.26] 0.88 [0.49, 1.58] 0.94 [0.55, 1.62] 0.79 [0.42, 1.51] 1.01 [0.72, 1.41] 1.06 [0.74, 1.50] 2.68ⴱ [1.85, 3.87] 1.85ⴱ [1.31, 2.62] 1.27 [0.89, 1.79] 1.19 [0.84, 1.70]
⫺.06 [⫺.18, .06] ⫺.04 [⫺.28, .20] .05 [⫺.20, .30] ⫺.01 [⫺.21, .19] ⫺.13 [⫺.39, .13] .03 [⫺.09, .15] ⫺.00 [⫺.14, .13] .07 [⫺.08, .22] .41ⴱ [.24, .57] .10 [⫺.03, .22] ⫺.02 [⫺.13, .09]
.01 [⫺.12, .14] ⫺.51ⴱ [⫺.73, ⫺.29] .04 [⫺.27, .19] ⫺.20 [⫺.41, ⫺.01] ⫺.06 [⫺.31, .19] ⫺.01 [⫺.13, .11] .11 [⫺.02, 0.24] ⫺.05 [⫺.18, .07] .36ⴱ [.23, .49] ⫺.08 [⫺.20, .05] ⫺.09 [⫺.21, .04]
.04 [⫺.08, .16] ⫺.42ⴱ [⫺.64, ⫺.20] .11 [⫺.13, .35] ⫺.21 [⫺.42, ⫺.06] ⫺.18 [⫺.42, .06] .01 [⫺.11, .13] .08 [⫺.04, .20] ⫺.08 [⫺.21, .06] .37ⴱ [.22, .51] ⫺.14 [⫺.29, .01] ⫺.05 [⫺.18, .09]
Note. MPS ⫽ Marijuana Problem Scale; PHQ-9 ⫽ Patient Health Questionnaire–9; PSS-4 ⫽ Perceived Stress Scale– 4. Reported coefficients for continuous predictor variables are fully standardized; coefficients for categorical predictors are y-standardized. Parameters and standard errors were estimated by maximum likelihood with robust standard errors. ⴱ p ⬍ .01. a
or social purposes did not uniquely account for a significant proportion of variance in this outcome. Moreover, copingmotivated use, but not social- or enhancement-motivated use, is associated with MJ-related problems in this group. Using MJ to cope with negative emotions among emerging adults also appears to be uniquely associated with psychiatric symptoms, as measured by severity of depressive symptoms and degree of perceived stress, consistent with prior research (Mitchell et al., 2007). These data are the first to demonstrate the confluence of cannabis use disorder, MJ-related problems, and psychiatric symptoms in the same sample. In addition, a significant shortcoming of previous work was the exclusion of individuals who met DSM diagnostic criteria for Axis I psychopathology (Bonn-Miller, Vujanovic, et al., 2007; Bonn-Miller et al., 2008; Bonn-Miller & Zvolensky, 2009), a meaningful omission given the concern for mental health issues in these individuals. The acceptability of MJ use is growing in emerging adults (Keyes et al., 2011), a high-risk group for substance use disorders (SAMHSA, 2013). Although prior studies have shown an association between coping-motivated MJ use and a variety of negative psychological factors (e.g., Mitchell et al., 2007), little research has compared the relationship of coping-motivated use, relative to social- and enhancement-based use, to MJ-related problems and psychological variables. These are also the first results linking using MJ to cope with psychological distress to the newly defined DSM-5 cannabis use disorder. This new diagnostic category represents an important streamlining of the DSM’s cannabis abuse and dependence diagnoses while incorporating a severity dimension. This new approach is particularly relevant to clinicians working with emerging adults, because the DSM-IV classification system poorly quantified severity of use in this age group (Martin et al., 2006). This study had limitations. First, our primary measure of MJ use motives was adapted from an alcohol scale. Moreover, we did not measure conformity- or expansion-motivated use; these would be important to include in future research. Second, although copingmotivated use was significantly associated with negative psychological variables, our estimated standardized effect sizes suggest
that coping-motivated use might not be the only factor associated with these outcomes. Third, the sample was limited to emerging adults who had past-month MJ use, were not seeking treatment, and were sexually active. Although the sample had the strengths of not excluding those with Axis I psychopathology, being ethnically/ racially diverse, being nearly half female, and including a substantial number of emerging adults not currently in school (41%), it was not an epidemiological sample. Furthermore, ⬎ 50% of potential participants declined to participate in the study. Fourth, we did not use a diagnostic measure to assess the presence of major depressive disorder. Fifth, MJ-induced anxiety is one of the most commonly reported acute symptoms of MJ use (Crippa et al., 2009). Thus, it is possible that self-reported use of MJ to cope with distress is confounded by MJ-triggered symptoms. Finally, given the cross-sectional nature of the data, we were unable to examine the temporal relationship between coping-motivated use and psychological distress. Still, our findings suggest that assessment of use of MJ to manage psychological distress may be clinically important and, if found, signal the importance of a broad and careful mental health assessment. These results raise the question about how coping-motivated MJ use might improve or worsen one’s well-being. Although MJ may be perceived as beneficial in ameliorating symptoms of emotional distress, long-term MJ use for these purposes has been associated with deleterious consequences (Patrick, Schulenberg, O’Malley, Johnston, et al., 2011). More longitudinal research will be needed to examine if, despite being used with the intention of mitigating distress, coping-motivated use may actually worsen psychological health.
Conclusions MJ use is becoming more socially acceptable and common in emerging adults. These results help clinicians identify MJ-using individuals who are likely to also have psychological distress symptoms. It appears that there is an important subset of emerging adults who use MJ for coping purposes, and these individuals are at risk for a variety of MJ-related problems. Clinicians working
COPING-MOTIVATED MARIJUANA USE IN EMERGING ADULTS
with patients who use MJ to cope with negative emotions face the challenge of confronting misconceptions about the perceived benefit of using MJ to “treat” distress. If MJ users continue to be reluctant to engage in drug counseling or to reduce use, despite having substance-related problems, clinicians must become more open to providing treatment such as alternative coping strategies for what these users might be more motivated to change, namely, their symptoms of psychological distress.
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Received December 8, 2014 Revision received March 2, 2015 Accepted March 9, 2015 䡲
