Abstract
We examined sociodemographic and psychosocial risk factors that moderate the (poly) substance use and dating violence victimization and perpetration relationship among emerging adults. Using an ethnically diverse sample (N = 698), we used latent class analyses to identify mutually exclusive groups based on monthly and past-year substance use. We then examined these groups as they relate to dating violence victimization and perpetration and the moderating effect of various risk factors. Five classes were identified based on substance use patterns: (a) Regular Alcohol use, (b) Polysubstance use, (c) Heavy Alcohol and Marijuana use, (d) Mild Alcohol use, and (e) Occasional Alcohol and Marijuana use classes. Participants in the Polysubstance use class were the most likely to perpetrate dating violence followed by Heavy Alcohol and Marijuana use, Occasional Alcohol and Marijuana use, Regular Alcohol, and Mild Alcohol use classes. Similarly, participants in the Polysubstance use class were the most likely to be victims of dating violence followed by Occasional Alcohol and Marijuana, Heavy Alcohol and Marijuana, Regular Alcohol, and Mild Alcohol use classes. Depending on substance use class, gender, ethnicity, socioeconomic status, history of dating violence, and trauma symptoms differentially influenced dating violence perpetration and victimization at 1-year follow-up. Our findings support the need to comprehensively address dating violence among emerging adults. Intimate partner violence prevention and intervention programs may benefit from targeting emerging adults who misuse substances and incorporating substance use interventions into dating violence prevention efforts.
Dating violence is a prevalent public health problem among adolescents and emerging adults. Nationally representative studies cite physical and sexual dating violence at comparable rates, affecting approximately 1 in 10 adolescents in Grades 9–12 more than a 12-month period (Centers for Disease Control and Prevention, 2013). Psychological dating violence is posited to occur with greater frequency affecting 30% of the adolescents aged 12–21 (Halpern et al., 2001). This prevalence is alarming considering the detrimental effects dating violence has on victims, particularly at such critically important developmental ages. Victims of dating violence have a heightened risk of mental health disorders, increased substance use, greater rates of academic drop out, and lower psychosocial functioning, relative to nonvictims (Banyard & Cross, 2008 ; Brown et al., 2009; Ellis et al., 2009). Negative consequences impel the field to examine the potential risk factors that increase the likelihood of perpetration and victimization, as well as related areas for intervention.
Substance Use and Dating Violence
Substance use is frequently cited as both a consequence of and precursor to dating violence victimization (Nowotny & Graves, 2013; Reingle et al., 2014; Smith et al., 2012) and perpetration (Leonard, 2005; Reyes et al., 2014; Smith et al., 2012; Testa & Brown, 2015). Substance misuse, including misuse of alcohol, marijuana, illicit substances (e.g., cocaine, heroin, amphetamines, hallucinogens), and prescription medication is prevalent among emerging adults (Substance Abuse and Mental Health Services Administration, 2015). While prior research supports the relationship between singular substances and dating violence perpetration and victimization among emerging adults (Haynie et al., 2013; Shorey et al., 2011), there is limited research examining emerging adults’ dating violence as it relates to the use of multiple substances and the particular patterns of substance use.
Emerging adults’ use of multiple substances, or polysubstance use (i.e., the use of two or more substances either simultaneously or concurrently during a given time period), is particularly concerning given its prevalence and its association with problematic behaviors such as aggression (Connor et al., 2014; Gilreath et al., 2014; Kokkevi et al., 2014McCabe et al., 2006; Wanner et al., 2009). Examination of patterns of polysubstance use among adolescents showed that the number of latent classes tends to range from three to six (Tomczyk et al., 2016). Common latent classes included a no or low substance use class, an alcohol only class with varying severity of alcohol use, and polysubstance use classes, which frequently included alcohol, tobacco, and/or marijuana, with varying severity of use (Tomczyk et al., 2016). Polysubstance use, particularly marijuana and alcohol use and alcohol and prescription drug misuse, is linked to dating violence perpetration and victimization among emerging adults (Espelage et al., 2018; Low et al., 2017; Parker & Bradshaw, 2015). However, research has yet to examine polysubstance use that includes substances such as cocaine, amphetamines, inhalants, hallucinogens, and ecstasy as it relates to dating violence perpetration and victimization.
Substance use may relate to emerging adult’s dating violence victimization and perpetration due to the singular or multiple substance’s pharmacological effects. That is, the disinhibition, impaired cognitive function, increased arousal, and irritability associated with using substances may increase the likelihood for violence perpetration and victimization (Pihl & Hoaken, 1997; Pihl & Peterson, 1995; Virkkunen & Linnoila, 1993; White, 1997). It is also possible that substance use and dating violence cooccur through the tendency that problematic behaviors have a propensity to cluster (Dryfoos, 1990; Jessor, 1991; Pharo et al., 2011). Indeed, polysubstance use is linked to risky sexual behaviors (Connell et al., 2009), frequency of substance use (Conway et al., 2013; Dierker et al., 2007), and dating violence (Parker & Bradshaw, 2015). While substance use is a robust predictor of dating violence, many individuals who use substances do not engage in dating violence, suggesting the need to examine individual risk factors that moderate the (poly) substance use and dating violence relationship (Foran & O’Leary, 2008; Leonard, 2005; Moore et al., 2008; Reyes et al., 2014; Shorey et al., 2011).
Sociodemographic Risk Factors
Sociodemographic factors, including age, gender, parental education, and ethnicity may moderate the association between patterns of substance use and dating violence perpetration and victimization. With respect to age, it may be that substance use has a more substantial impact on neurological functioning earlier in their development (De Bellis et al., 2000), resulting in a stronger relationship between substance use and dating violence. However, it could also be that as age increases, adolescents are more likely to engage in several risky behaviors, resulting in a strong link between substance use and dating violence. These points likely contribute to whether a relationship exists between age and dating violence (Karakurt & Silver, 2013; Reuterman & Burcky, 1989; Tomczyk et al., 2016; Wolitzky-Taylor et al., 2008). Of these mixed results, few studies have examined this relationship, or the moderating impact of age, in samples of adolescents. Considering these relationships will extend our understanding of the patterns and risk factors of adolescent dating violence.
Gender may also be significantly related to the association between substance use and dating violence. In a national representative sample, Haynie et al. (2013) revealed that females involved in dating violence were more likely to smoke cigarettes and use marijuana compared with males who were involving in dating violence. In another study using a national sample, females who used synthetic cannabinoids were more likely to be victims of physical dating violence compared with males who used synthetic cannabinoids (Ihongbe & Masho, 2018). Research also suggests that longitudinal predictors of dating violence among adolescents may have differing impacts across gender (Foshee et al., 2001). For instance, one study indicated that belonging to a peer group with experience in dating violence and alcohol use predicted dating violence perpetration among women whereas only attitudes endorsing the acceptability of dating violence predicted dating violence perpetration for men (Foshee et al., 2001). It has been posited that women may respond to alcohol differently, including being less likely to respond aggressively when drinking while simultaneously putting them at increased risk for victimization (Nolen-Hoeksema, 2004). An examination on how gender affects the relationship between substance use and dating violence will inform prevention and intervention programs.
Ethnicity and socioeconomic status (SES) are also important to consider when examining the link between substance use and dating violence. For instance, research has called for increased accessibility to services for Hispanic individuals as they may be less likely to seek assistance for dating violence relative to others (Lipsky et al., 2006). In addition, dating violence among African American adolescents has shown to occur at higher rates than other ethnic groups (Carver et al., 2003; Halpern et al., 2001; Haynie et al., 2013). Schnurr and Lohman (2008) found that Hispanic males (but not Hispanic females or African American females and males) who used substances in early adolescence were significantly more likely to perpetrate dating violence at 6-year follow up (Schnurr, and Lohman, 2008). Little is known with respect to ethnicity as a moderating variable for the link between substance use and dating violence. This lack of knowledge is surprising given the plethora of studies examining substance use and race/ethnicity (Chen & Jacobson, 2012; Shih et al., 2010) and dating violence and race/ethnicity (Foshee et al., 2010; Rojas-Gaona, et al., 2016), respectively. Similarly, there is a paucity of research examining the moderating role of SES, despite findings that youth from low-income households may have an increased likelihood of experiencing dating violence (Foshee et al., 2009). We addressed these shortcomings in the current study.
Prior experience with dating violence is among the strongest predictors of future dating violence. Longitudinal research showed that for both men and women, those who experience dating violence as an adolescent are more likely to experience adult dating violence victimization (Exner-Cortens et al., 2013). Moreover, studies have shown that dating violence victimization in adolescence predicts dating violence victimization and perpetration in young adulthood (Gómez, 2011), and that prior perpetration predicts future dating violence perpetration (Gidycz et al., 2007). Thus, research is needed to examine how prior dating violence experiences moderate the relationship between patterns of (poly) substance use and dating violence.
Psychosocial Risk Factors
Mental health problems are frequently comorbid with substance use and dating violence victimization and perpetration among adolescents and adults (Kilpatrick et al., 2003; Rhodes et al., 2009; Schneider et al., 2009). Adults with symptoms of depression and post-traumatic stress disorder (PTSD) are more likely to perpetrate and be victims of dating violence than those without these symptoms (Reingle et al., 2014). Hostility has also been associated with dating violence (Birkley & Eckhardt, 2015; Leen et al., 2013) and has been shown to moderate the relationship between alcohol use and marital aggression among men (Leonard & Blane, 1992). While these are well-known risk factors of dating violence, research has yet to examine their role as moderators of (poly) substance use and dating violence.
Current Study Purpose and Hypotheses
We investigate how different patterns of (poly) substance use (i.e., alcohol, tobacco, marijuana, prescription drugs, and other substances) influence dating violence, as well as examine whether sociodemographic (i.e., age, gender, ethnicity, SES) and psychosocial variables (i.e., hostility, PTSD symptoms, depression symptoms) influence dating violence based on patterns of substance use. Given previous research (Tomczyk et al., 2016), we hypothesized that (a) poly (or dual) substance users will report higher dating violence victimization and perpetration relative to subgroups who used no substances or a single substance and (b) sociodemographic and psychosocial risk factors will differentially relate to dating violence victimization and perpetration depending on patterns of substance use.
Method
Participants and Procedure
A total of 698 emerging adults (62.6% female; mean age = 18.06, standard deviation [SD] = 0.79) participated in Wave 5 (spring 2014) and Wave 6 (spring 2015) of an ongoing longitudinal study (N = 1,042). Participants were recruited in 2010 from public high schools throughout southeast Texas (response rate: 62% at Wave 1; see Temple et al., [2013] for more details). Written parental consent and student assent were obtained following institutional review board (IRB) approval from the last author’s institution. Participants reconsented when they reached the age of 18. Beginning with Wave 5, all participants completed web-based surveys and were reimbursed via a gift card to an online retailer in the amounts of US$20 (Wave 5) and US$30 (Wave 6). At Wave 5, participants’ ethnic/racial identities were Hispanic (33.1%), White (27.4%), African American (27.2%), and other (12.3%). Occupational and educational status included attending college/trade school (even if working; 70.2%), working (not in school; 20.2%), not attending school or working (8.9%), and attending high school (0.7%). Most participants lived with their family (56.3%), followed by friends/roommates (28.4%), romantic partners (9.8%), and alone (5.5%). With respect to parent education, 15.9% had less than high school graduation, 16.6% had a high school diploma, 27.8% had some college or training after high school, and 38.7% completed college.
Measures
Yearly substance use (Wave 5; indicators in latent class analysis)
Using a yes/no format, participants reported their past-year use of alcohol, tobacco, marijuana, prescription medication, cocaine, amphetamines, inhalants, hallucinogens, and ecstasy. Due to relatively low prevalence of the latter five substances, we created a dichotomous other “hard” drug use based on positive endorsement of any of these substances.
Monthly substance use (Wave 5; indicators in latent class analysis)
Participants reported the number of days in the past month they used alcohol, marijuana, episodic heavy drinking, prescription medication (i.e., “During the past 30 days, on how many days did you have at least one drink of alcohol/use marijuana/participated in binge drinking/use prescription medication that were not prescribed?”). Episodic heavy drinking was defined as “five or more drinks for boys and four or more drinks for girls.” Exemplars of prescribed medication were provided (“Xanax, Vicodin, Oxycontin, Percocet, Ritalin, Adderall, Ludes, Vitamin R, Handlebars”). To account for constraints in our analyses, we created binary items (yes/no) on past-month substance use. Specifically, when a participant reported alcohol use (or any substance) at least one day in the past month, we coded their response as past-month alcohol (or any specific substance) use.
Dating violence victimization and perpetration (Wave 5 and 1-year follow-up)
Forty-two items from The Conflict in Adolescent Dating Relationships Inventory (Wolfe et al., 2001) measured past-year physical (4 items) and psychological (17 items) victimization (total 21 items) and perpetration (total 21 items) with a yes-or-no format. Example items for victimization include “He/She threatened to end the relationship” and “He/She insulted me with put downs.” Perpetration items included “I spread rumors about him or her,” and “I kicked, hit, or punched him or her.” Because physical and psychological dating violence cooccur (Choi et al., 2017; Choi & Temple, 2016), we summed all 21 items for victimization (range: 0–21) and perpetration (range: 0–21). The internal consistency of the measure was .90 for victimization at both waves, and .87 and .89 for perpetration at Waves 5 and 6, respectively.
Depressive symptoms (Wave 5)
The Center for Epidemiologic Studies Short Depression Scale (Andersen et al., 1994) assessed depressive symptoms using a 4-point scale (1 = “less than 1 day” and 4 = “5–7 days”). Although the survey originally included 10 items, 2 items had poor correlations with other items (e.g., r = −.02) and were thus dropped in favor of higher internal consistency (Nowakowski et al., 2016). We created a composite variable by taking the average score of the eight items, with higher scores suggesting greater depressive symptoms (e.g., “I had trouble keeping my mind on what I was doing”; “I felt depressed”; Cronbach’s α =.82).
Hostility (Wave 5)
Hostility was measured with the six items subscale of the Symptom CheckList-90 (SCL-90; Derogatis, 1983). The six items were averaged, with higher scores suggesting greater hostility. Using a 4-point scale (1 = “never” and 4 = “most of the time”), example items include: In general, how often do you “have temper outbursts you can’t control?,” “have urges to beat, injure, or harm someone?,” and “shout or throw things?” (Cronbach’s α = .79).
Trauma symptoms (Wave 5)
Four items (yes/no format) from the primary care PTSD screen (PC-PTSD; Prins & Ouimette, 2004) were summed to create a composite variable of trauma symptoms. Thus, higher scores indicated greater trauma-related symptoms. Using the premise “Have you had any experience in your lifetime that was so frightening, horrible, or upsetting that, in the PAST MONTH you,” example items included: “Had nightmares about it or thought about it when you did not want to?” and “Tried hard not to think about it or went out of your way to avoid situations that reminded you of it?” The PC-PTSD has been shown to be a valid measure with an acceptable level of internal consistency (Kimerling et al., 2006; Cronbach’s α = .81).
Demographics
Participants reported gender identity, racial/ethnic identity, age, and parents’ highest education (as a proxy for SES). Gender was dummy coded (female = 1 vs. male = 0). For racial/ethnic identity, three dummy-coded variables were created. White participants served as the reference group (e.g., Hispanic = 1 vs. White = 0; African American = 1 vs. White = 0; other races/ethnicities = 1 vs. White = 0).
Analytical Plan
We used latent class analysis (LCA) to identify homogeneous subgroups based on patterns of participant substance use at Wave 5. LCA is a statistical tool used to identify similar patterns of behaviors within subgroups while also differentiating these patterns between subgroups by accounting for measurement error (Collins & Lanza, 2010). That is, LCA can estimate the prevalence of latent classes and the parameters of item–response probabilities (Collins & Lanza, 2010). Because estimates in LCA can be influenced by additional variables such as predictors for membership in classes or distal outcomes (Asparouhov & Muthén, 2014a; Vermunt, 2010), we used a three-step LCA in Mplus 7.4 (Muthén & Muthén, 1998–2015) to answer our research questions. This approach enables the analysis of predictor estimates or outcome estimates without influencing parameters (e.g., item–response probabilities; see Asparouhov & Muthén, 2014a for additional details). To identify latent substance use classes, we included the following nine indicators: past-year use of alcohol, tobacco, marijuana, prescription medication, and hard drugs, as well as past-month use of alcohol, marijuana, episodic heavy drinking, and prescription medication.
First, we used LCA to identify latent substance use classes with these nine indicators. To identify the optimal number of latent classes, we used the (adjusted) Bayesian information criterion (BIC), the adjusted Lo-Mendell–Rubin likelihood ratio test (Lo et al., 2001), and theoretically meaningful interpretations based on substance LCA literature (Tomczyk et al., 2016). Once the optimal number of classes was identified, we compared the means in a distal outcome such that dating violence victimization and perpetration at 1-year follow-up significantly differed across these latent classes using a Wald test with BCT command (Asparouhov & Muthén, 2014b). Finally, we used a manual three-step estimation procedure (Asparouhov & Muthén, 2014a) to examine how gender (reference group: male), race/ethnicity (reference group: White), age, parental education, depressive symptoms, hostility, trauma symptoms, and dating violence perpetration and victimization at Wave 5 influenced dating violence perpetration and victimization at the 1-year follow-up depending on the latent substance classes. This analysis allowed us to explore a moderator role of latent substance use class in a linear regression to predict dating violence victimization and perpetration. We used full information maximum likelihood to handle missing responses (Enders & Bandalos, 2001).
Results
Table 1 includes frequency, means, and standard deviations across all variables of interest. The most frequently used substance in the past year was alcohol (67.2%) followed by marijuana (37.9%), tobacco (24.5%), “hard” drugs (10.8%), and nonmedical use of prescription medication (9.4%). Participants reported monthly alcohol use (52.2%), monthly episodic heavy drinking (33.4%), monthly marijuana use (26.0%), and monthly nonmedical use of prescription medication (6.1%). Perpetration of dating violence slightly increased whereas victimization slightly decreased at the 1-year follow-up.
Descriptive Statistics.
Latent Substance Use Class and Different Dating Violence Among These Classes
Latent substance use class
Based on the fit indices (Table 2), five latent substance classes were selected. To test possible gender difference in LCA, we compared men and women using the same nine indicators. The same optimal number of classes emerged for men and women. We also compared one model with varying item–response probabilities among men and women (BIC = 5,873.974) to a model constraining item–response probabilities (BIC = 5,622.758), which indicated that females and males had an equivalent number of classes. Thus, rather than separately investigating LCA among men and women, we used gender as a covariate in the three-step LCA. As shown in Figure 1, the following five substance classes emerged: (a) Regular Alcohol use (n = 178, 25.7%), (b) Polysubstance use (n = 46, 6.6%), (c) Heavy Alcohol and Marijuana use (n = 145, 20.9%), (d) Mild Alcohol use (n = 264, 38.1%), and (e) Occasional Alcohol and Marijuana use (n = 60, 8.7%). The Regular Alcohol use class had high item–response probabilities regarding yearly (1.00) and monthly alcohol use (.96) and a moderate degree of item–response probabilities on episodic heavy drinking (.53). The Polysubstance use class had higher item probabilities across all substances including yearly alcohol (1.00), tobacco (.66), marijuana (.93), nonmedical use of prescription drugs (1.00), and “hard” drugs (.65), as well as monthly alcohol (.97), marijuana (.82), episodic heavy drinking (.82) and nonmedical use of prescription drugs (.86). The Heavy Alcohol and Marijuana use class had a higher item probability on yearly (1.00) and monthly (.99) alcohol use, monthly episodic heavy drinking (.67) and yearly (1.00) and monthly marijuana use (.79). The Mild Alcohol use class had a relatively low item probability of alcohol use (.22) and the lowest item probabilities on the remaining substances. Finally, Occasional Alcohol and Marijuana use class had higher item–response probabilities on yearly marijuana use (.97) and alcohol use (.62) and moderate degree of item–response probability on monthly marijuana use (.48), relative to the other substance indicators.
LCA Fit Index.
Note. LCA = latent class analysis; AIC = Akaike information criterion; BIC = Bayesian information criterion; LMRT = Lo-Mendell–Rubin likelihood ratio test.
p <. 05. ***p <.001.

Latent substance classes.
Dating violence comparisons among latent substance use classes
At the 1-year follow-up, the Polysubstance use class (M = 4.72, SD = 0.74) had the highest dating violence perpetration scores followed by Heavy Alcohol and Marijuana use (M = 4.23, SD = 0.44), Occasional Alcohol and Marijuana use (M = 4.08, SD = 0.60), Regular Alcohol use (M = 3.66, SD = 0.34), and Mild Alcohol use (M = 3.06, SD = 0.27) classes (see Figure 2). Wald-test showed that the Polysubstance use, χ2(1) = 4.46, p = .04, and Heavy Alcohol and Marijuana use, χ2(1) = 5.22, p = .02, classes had significantly greater dating violence perpetration compared with the Mild Alcohol use class. With respect to victimization, the Polysubstance use class (M = 5.03, SD = 0.79) had the highest dating violence victimization scores followed by the Occasional Alcohol and Marijuana use (M = 4.61, SD = 0.72), Heavy Alcohol and Marijuana use (M = 3.88, SD = 0.39), Regular Alcohol use (M = 3.68, SD = 0.36), and Mild Alcohol use (M = 3.21, SD = 0.29) classes. The Wald-test showed that the Polysubstance use class had significantly greater dating violence victimization scores compared with the Mild Alcohol use class, χ2(1) = 4.72, p = .03. The Occasional Alcohol and Marijuana use class had marginally greater victimization scores relative to the Mild Alcohol use class, χ2(1) = 3.25, p =.07.

Perpetration and victimization scores each substance use class.
Sociodemographic and psychosocial variables and dating violence among latent substance use classes
Gender, race/ethnicity, parental education, age, depressive symptoms, trauma symptoms, hostility, and dating violence victimization and perpetration at Wave 5 were included as covariates in the LCA to examine how these variables influence dating violence perpetration (BIC = 23,262.62) and victimization (BIC = 23,338.07) at the 1-year follow-up (see Table 3 for perpetration and Table 4 for victimization). In the Regular Alcohol use class, participants with higher dating violence perpetration scores at Wave 5 (B = 0.66, standard error [SE] = 0.17, p <.001) were more likely to perpetrate dating violence at 1-year follow up, whereas participants reporting greater dating violence victimization at Wave 5 (B = 0.45, SE = 0.21, p <.05) were more likely to experience dating violence victimization at the 1-year follow-up.
Moderator Effects of Each Class on Dating Violence Perpetration.
Note. White participants were the reference group for racial/ethnic comparisons. Men were the reference group for gender comparison.
p < .05. **p < .01. ***p < .001.
Moderator Effects of Each Class on Dating Violence Victimization.
Note. White participants were the reference group for racial/ethnic comparisons. Men were the reference group for gender comparison.
p < .05. **p < .01. ***p < .001.
In the Polysubstance use class, White participants were more likely to experience dating violence—both perpetration (B = −3.68, SE = 1.33, p <.01; reference group: White) and victimization (B = −4.61, SE = 1.46, p <.01)—compared with “others” in the same class. Furthermore, in the Polysubstance use class, participants with greater trauma symptoms scores were more likely to be victims (B = 1.78, SE = 0.43, p <.001) and perpetrators (B = 1.61, SE = 0.49, p <.01) of dating violence compared with youth with lower trauma symptoms scores. In the Heavy Alcohol and Marijuana use class, African American (B = 2.19, SE = 1.00, p <.05) participants and participants with greater dating violence perpetration experiences at Wave 5 (B = 0.64, SE = 0.21, p <.05) reported greater dating violence perpetration scores at 1-year follow-up, relative to White participants and participants with less perpetration of dating violence in the same class.
In the Mild Alcohol use class, participants with higher dating violence perpetration scores at Wave 5 (B = 0.60, SE = 0.10, p <.001) were more likely to perpetrate dating violence, whereas youth reporting greater dating violence victimization at Wave 5 (B = 0.44, SE = 0.19, p <.05) were more likely to experience dating violence at 1-year follow-up relative to counterparts in the same class. Finally, in the Occasional Alcohol and Marijuana use class, women participants (B = 2.24, SE = 1.00, p<.05), White participants (B = −5.57, SE = 2.37, p <.01), and participants with lower parental education (B = −1.54, SE = 0.50, p <.01) were more likely to perpetrate dating violence compared with their counterparts in the same class. Also, participants whose parents had lower levels of education (B = −1.00, SE = .05, p <.05) were more likely to be victims of dating violence 1 year later, compared with their same-class counterparts.
Discussion
This study extends prior research by examining how different patterns of substance use influenced dating violence and how sociodemographic variables (e.g., gender identity, race/ethnicity) and psychosocial variables (e.g., hostility, trauma-related, and depressive symptoms) could exacerbate these influences. This study also expands prior studies by examining latent classes of polysubstance use as it relates to dating violence by including drugs not previously included (i.e., cocaine, amphetamines, inhalants, hallucinogens, and ecstasy). The latent classes that emerged included Polysubstance use, Regular Alcohol use, Mild Alcohol use, Heavy Alcohol and Marijuana use, and Occasional Alcohol and Marijuana use classes. These classes are largely consistent with those found in the prior research (Tomczyk et al., 2016). A systematic review of 23 studies (Tomczyk et al., 2016) concluded that two latent classes are commonly found: a low substance use class and a polysubstance use class. This review demonstrated that the alcohol onlyuse class is commonly illustrated in most studies. We extended this finding by revealing Heavy and Occasional Alcohol and Marijuana use classes. This finding might reflect the current adolescent substance use trend. Although traditionally alcohol has been the most common and accessible substance compared with other drugs, marijuana has been increasingly accessible. Furthermore, the perceived harmfulness of marijuana use has decreased as its widespread legalization in the United States (Keyes et al., 2016; Cerdá et al., 2017). This might account for the emergence of the alcohol and marijuana classes.
Polysubstance users, as well as alcohol and marijuana users, were at greatest risk for dating violence victimization and perpetration compared with the Mild Alcohol use class. This is consistent with the previous research. For example, in a diverse sample of high-school adolescents in Maryland, prior dating violence victimization resulted in an increased likelihood of polysubstance use (i.e., alcohol, marijuana, nicotine, and prescription drugs; Parker & Bradshaw, 2015). Adolescents who were polysubstance users of both alcohol and prescription drugs, compared with those who only used alcohol, were more likely to perpetrate and be victims of dating violence (Espelage et al., 2018). While little research has examined mechanisms underlying the link between polysubstance use and dating violence victimization and perpetration, theories related to the role of substance use, in general, in dating victimization and perpetration are common. As the use of substances alters judgment, it is possible that emerging adults who use substances have an impaired ability to recognize and defend themselves from dating situations (Malik et al., 1997) or to misinterpret behaviors as threatening and react in kind (Rothman et al., 2012). This notion is consistent with empirical work demonstrating a temporal relationship between substance misuse and dating violence victimization and perpetration (Moore et al., 2011; Shorey et al., 2016; Stuart et al., 2013; Temple et al., 2013). Given deficits in multiple areas of executive functioning found among polysubstance users (Verdejo-Garcıa et al., 2005), it is possible that polysubstance using emerging adults are at a greater susceptibility to dating violence perpetration and victimization due to increased impairments.
Dating violence victimization and perpetration differed among ethnic groups, indicating that some individuals may be at increased or decreased risk depending on patterns of substance use. Our finding showed that being White increased dating violence victimization and perpetration in the Polysubstance use class and the Occasional Alcohol and Marijuana use class. Prior research highlights the inconsistency of findings related to race/ethnicity and dating violence victimization and perpetration, with some studies finding a particular racial/ethnic group as being a risk factor for and other studies categorize the same group as a protective factor against dating violence (Dardis et al., 2015; Vezina & Hebert, 2007). While it is unclear what accounts for race/ethnicity differences in dating violence victimization and perpetration among emerging adults, the larger research literature suggests that differences in help-seeking behavior may help explain these differences (Lipsky & Caetano, 2007; Lipsky et al., 2006). For example, among victims of dating violence, African American women, relative to other groups, were more likely to utilize help-seeking behaviors (e.g., police assistance) and non-Hispanic White women and African American women were more likely to utilize emergency services relative to their Hispanic counterparts (Lipsky et al., 2006). White youth have been shown to be more likely to receive treatment for substance use disorders compared with their African American and Hispanic counterparts (Alegria et al., 2011; Cummings et al., 2011). These differences in treatment and help seeking coupled with the strong link between substance use and dating violence (Leonard, 2005; Reyes et al., 2014; Smith et al., 2012; Testa & Brown, 2015) could account for our finding that African Americans in the Heavy Alcohol and Marijuana use classes (compared with their White counterparts) reported more perpetration of dating violence at the 1-year follow-up.
Parental education was inversely associated with dating perpetration and victimization in the Occasional Alcohol and Marijuana use class, which suggests that emerging adults from lower SES households were at an increased likelihood of perpetrating and being victims of dating violence even though they used less substances. This suggests that variables other than substance misuse are important in predicting dating violence. Among those in the Occasional Alcohol and Marijuana use class, women were at a greater risk for dating violence perpetration, suggesting that alcohol may be a more salient risk factor for women compared with men (Foshee et al., 2001).
Emerging adults with a history of perpetrating dating violence in the Regular Alcohol use, Heavy Alcohol and Marijuana use, and Mild Alcohol use classes were more likely to perpetrate violence over time, even though their perpetration scores were lower at baseline than emerging adults in the Polysubstance use class. In addition, emerging adults with a history of dating violence victimization in the Regular Alcohol use and Mild Alcohol use classes were more vulnerable to future dating violence victimization. This is consistent with the past findings that prior experiences with dating violence predict future experiences with dating violence (Exner-Cortens et al., 2013; Gidycz et al., 2007). These findings lend support to the pharmacological effects of alcohol hindering cognitive and attentional resources (Steele & Josephs, 1990) leading to dating violence perpetration or that victims of dating violence may be more likely to use alcohol to cope with erstwhile violence (Kaysen et al., 2007).
Among individuals engaging in polysubstance use, those with more trauma-related symptoms were more likely to be victims and perpetrators of dating violence at follow-up. Prior research has found that trauma mediates the link between dating violence as an adolescent and dating violence as an emerging adult (Jouriles et al., 2017). Furthermore, trauma symptoms secondary to childhood maltreatment predict future dating violence perpetration and victimization (Wolfe et al., 2004). Trauma has also been linked to substance use (Sullivan et al., 2016), which is related to increased risk for victimization and perpetration (Espelage et al., 2018; Testa et al., 2003).
Age did not moderate the relationship between substance use classes and experiences with dating violence. It is possible that age did not emerge as an important factor given our exclusive focus on emerging adults, who are similar neurodevelopmentally and in their risk for engaging in risky behaviors (Spear, 2000). Symptoms of depression also did not emerge as a moderator of the link between substance use and dating violence. It may be that these symptoms are less salient risk factors as trauma-related symptoms. Previous research has demonstrated that symptoms of depression only affect certain forms of dating violence (e.g., psychological abuse), while trauma-related symptoms were linked to all forms of dating violence (Eshelman & Levendosky, 2012). The fact that we only assessed depression symptoms in the past week may also have affected results. Finally, hostility did not emerge as a moderator, suggesting that other factors (e.g., substance use; Stith et al., 2004) may be more important in predicting physical dating violence.
Limitations
Findings should be considered several limitations. First, we limited analyses to presence/absence of physical and psychological dating violence. Including other forms (e.g., sexual assault, stalking) and the intensity/frequency of dating violence would have strengthened our understanding of how patterns of substance use influence victimization and perpetration given different individual characteristics (e.g., gender, PTSD). Second, despite the cooccurrence of physical and psychological dating violence (Choi et al., 2017; Choi & Temple, 2016), it is possible that patterns of substance use differently influence people who experience either of these forms of violence alone. Third, while several covariates were included (e.g., ethnicity, SES, mental health), other possible variables may also be important in explaining the current finding. For instance, dysregulated emotion has been associated with post-traumatic stress, depressive symptoms, and substance use (Bekh et al., 2011). Finally, the actual quantity of substances used (e.g., frequency or amount) was not considered. It is likely that emerging adults with greater frequency and amount of alcohol use have a greater likelihood of victimization relative to those who used multiple substances once.
Implications and Conclusion
Our findings support the need to comprehensively research dating violence among emerging adults, and that interventions may need to be individually tailored. For example, individuals with a history of polysubstance use may be less likely to perpetrate dating violence if interventions target their symptoms of trauma. Conversely, to effectively reduce dating violence among individuals who regularly use alcohol and/or marijuana we may need to target their substance use. For individuals with limited alcohol use, prior dating violence emerged as the most important predictor of future dating violence; interventions targeting substance use for these individuals may do little to prevent future dating violence.
Taken together, our findings provide additional evidence linking substance misuse and violence (Duke et al., 2018; Stith et al., 2004) and add to the growing call that prevention programs should be multifaceted and targeted the shared risk and protective factors of multiple problem behaviors (e.g., Fourth R; Wolfe et al., 2009). Furthermore, our findings suggest that interventions may be strengthened by tailoring programming to subgroups based on ethnicity and/or gender. Results also emphasize the potential need to treat the comorbid problems of substance misuse and mental health (e.g., PTSD), especially among poly substance users.
Footnotes
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research was supported by Award Number K23HD059916 (PI: Temple) from the Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD) and 2012-WG-BX-0005 (PI: Temple) from the National Institute of Justice (NIJ). The content is solely the responsibility of the authors and does not necessarily represent the official views of NICHD or NIJ. This work would not have been possible without the permission and assistance of the schools and school districts.
