According to the Global Status Report on Alcohol and Health 2018, among young adults between the ages of 20–39 years old, approximately 13.5% of all deaths are the result of alcohol consumption; moreover, the peak of alcohol consumption in young adults falls between the 20 and 24 years (World Health Organization, 2018), corresponding with college ages. In Ecuador, based on the latest Report on Drug Use in the Americas, 2019, prevalence of alcohol consumption in the last month among college students is 51%, and a total of 41% of alcohol users reported problematic levels of consumption, systematically higher in male than female college students (Organization of the American States, 2019).

Despite the great influence of diagnostic approaches to alcohol use disorders (AUD) and other-related mental health problems, such as depression and anxiety (Castillo-Carniglia et al., 2019; McHugh and Weiss, 2019), some studies argue that psychiatric gnosologies must be updated to fulfill their purpose in research and clinical practice (Carragher et al., 2015; Hofmann and Hayes, 2019). Therefore, a new transdiagnostic approach is proposed, which goes beyond the traditional diagnostic limits, and can provide a new perspective into how to account for AUD and other mental health problems, thus having a better classification system, compared to the existing standard (Dalgleish et al., 2020). This new approach arises from a series of findings that suggest that the commonalities between the different disorders should be taken into account for evaluation and treatment (Nolen-Hoeksema and Watkins, 2011).

In this context, some transdiagnostic factors have drawn special attention in AUD and other mental health-related problems, being psychological (in)flexibility one of the key transdiagnostic clinical variables. This construct, also known as experiential avoidance, is defined as the tendency to control, avoid, or suppress the intensity and/or frequency of thoughts and feelings, even when doing so generates behavioral harm (Hayes et al., 1996), and may contribute to the development, maintenance, and exacerbation of AUD among college students (Levin et al., 2012). Second, psychological stress also plays a crucial role within this transdiagnostic emotional vulnerability model, and it is defined as a subjective perception of not being able to control or foresee the results of our behavior (Cohen et al., 1983), which has also been related to AUD in college students (Anthenelli, 2012; Keyes et al., 2012; Karyotaki et al., 2020).

Previous studies have warned about the particularly high and continuously growing rates of problematic alcohol consumption among college students in Ecuador (Ruisoto et al., 2016; Aguilar et al., 2022), but successful assessment models accounting for this problematic behavior and gender differences remain a challenge, in particular how key transdiagnostic variables moderate and/or meditate alcohol consumption (Nolen-Hoeksema, 2004; Dodd et al., 2010; Heidari et al., 2018). With the purpose of overcoming this gap in the literature, the aim of this study was to examine gender differences in psychological stress and inflexibility as transdiagnostic predictors of problematic alcohol consumption in a large sample of college students in Ecuador. Furthermore, we examined whether psychological inflexibility and psychological stress mediate the relationship between gender and alcohol consumption, and whether psychological inflexibility mediates the relationship between stress and alcohol consumption, moderated by gender.

The aim of this study was to examine gender differences in psychological stress and psychological inflexibility as transdiagnostic predictors of problematic alcohol consumption in a large sample of college students in Ecuador. To our knowledge, this is the first and largest study carried out in Ecuador examining alcohol consumption from both a transdiagnostic and gender perspective. Results have shown higher rates of alcohol consumption among men than women (of every 10 students with harmful alcohol consumption or dependence, seven are men), and higher levels of stress and psychological inflexibility among women than men. Interestingly, psychological inflexibility and stress mediated the effect of gender on alcohol consumption. Moreover, the mediation of psychological inflexibility between stress and alcohol consumption is positive and strong for both men and women, that is, gender moderated this mediation.

Firstly, men reported higher rates of alcohol consumption than women, being such result consistent with previous studies (UNODC, 2017; Gavurova et al., 2020; Villarosa-Hurlocker et al., 2020). Traditionally, research highlights that men drink more per drinking episode, that is, more often and over longer periods of time than women, while the last frequently use protective behavioral strategies (LaBrie et al., 2011). In this vein, Nolen-Hoeksema and Hilt (2006) found that men, compared to women, are more likely to be exposed to some risk factors, such as fewer social penalties for drinking and more positive expectations regarding alcohol consumption, among others as well as they might perceive alcohol use as a more acceptable activity because such consumption could be a part of their gender role (Perrotte et al., 2020). By contrast, the manifestation of alterations in cognitive and motor functioning, even with low doses of alcohol, in addition to its negative consequences on reproductive health, can dissuade most women from alcohol consumption, which would explain the presence of lower rates of alcohol use disorders and related problems, compared to men (Nolen-Hoeksema, 2004). Consumption in women, although lower than in men, according to Norberg et al. (2010), might be explained by social anxiety levels, a risk factor for them, who are more likely to report drinking in negative situations to deal with aversive emotions. In this regard, Engs and Hanson (1990) found that a higher percentage of college men are more likely than women to drink, to drink more often, to consume more, and to experience more drinking problems.

As has previously reported, several transdiagnostic factors have traditionally influenced severity of AUD, such as stress and psychological inflexibility. In particular, stress appears to be a serious problem for college students, who represent a very vulnerable group of the population (Robotham and Julian, 2006; Saleh et al., 2017) that commonly meet several health complaints and symptoms of depression, mood swings, and anxiety (Barbosa-Leiker et al., 2012). In the present study, women reported significantly higher levels of perceived stress than men students did. These findings are consistent with the results obtained in precedent research conducted among college students (Tavolacci et al., 2013; Varghese et al., 2015; Cavallo et al., 2016; Olfert et al., 2019; Seedhom et al., 2019; Choi, 2020; Meckamalil et al., 2020), and such gender differences may be explained due to women usually choose emotional-based coping styles (Tamres et al., 2002) as well as due to the presence of reduced stress resilience and coping resources (Kizhakkeveettil et al., 2017), leading to lower levels of wellbeing (Innes, 2017). Taking into account that there are several factors involved, more research is needed to understand and determine the differences in stress between the genders.

On the other hand, Psychological inflexibility is the avoidance of painful internal experiences, such as memories, thoughts, emotions, sensations, and representing a difficulty to act consistently according to significant personal values (Serowik and Orsillo, 2019). There is more and more research that supports the idea that psychological inflexibility is a transdiagnosis variable present in various psychological disorders (Kashdan and Rottenberg, 2010; Bond et al., 2011; Levin et al., 2014). For our purpose, psychological inflexibility has been theorized to play a role in the cause and maintenance of substance use disorders (Levin et al., 2012, 2014). In the present study, women reported significantly higher levels of psychological inflexibility than men students did, being such results consistent with precedent research (Levin et al., 2012; Mendoza et al., 2016; Serrano-Ibáñez et al., 2021). This could be explained due to the differences between men and women regarding their emotional processing (Whittle et al., 2011), as women tend to experience more negative affect than men and report more frequent and intense negative emotions (Brebner, 2003), which can lead them to avoid these emotions. It could also be explained due to the fact that higher levels of psychological inflexibility in women than in men may be related to traditional gender roles established in the Latino cultural context (Mendoza et al., 2016).

Furthermore, hierarchical regressions determined than psychological stress and inflexibility were significant predictors of alcohol consumption. Precedent studies (Kingston et al., 2010; Levin et al., 2012) also highlight the importance of psychological inflexibility in alcohol consumption. Levin et al. (2014) found that this variable was significantly related to having a comorbid depressive, anxiety, or substance use (including alcohol) disorder. In contrast, Serowik and Orsillo (2019) found little evidence for a unique association between inflexibility in alcohol consumption. Regarding psychological stress, it has been linked to an increased alcohol consumption (Sebena et al., 2012; Collins et al., 2014; Böke et al., 2019) in college students, and therefore, it is possible that students who are stressed drink alcohol as an experiential avoidance strategy. In view of the importance of knowing the variables that explain alcohol consumption and the variety of results found in the aforementioned studies, more research is needed.

The mediation model of psychological inflexibility and stress on the effect of gender on alcohol consumption was statistically significant. These results suggest for the first time in the literature that higher levels of psychological inflexibility and stress may play a role in alcohol consumption among college students, regardless of gender. Students (men and women) who consume higher amounts of alcohol do so not only because they experience negative emotional states, but also because they experience higher levels of stress. Eisenbeck et al. (2019) found that psychological inflexibility was related to psychological stress. Apparently, college students consume alcohol in order to avoid unpleasant thoughts, emotions, and sensations (Zgierska et al., 2009); in other words, those who drink motivated to change their unpleasant internal states to reduce their negative affects, are at greater risk of high alcohol consumption (Reynolds et al., 2015). Alcohol consumption, when it serves inflexible tendencies, could increase the level of unwanted thoughts and feelings, being possible that high levels of psychological inflexibility generate an endless cycle guided by unpleasant experiences and their avoidance, which in turn generates more unpleasant experiences. If a person believes that feeling stress or anxiety is a negative thing, they are likely to use problematic coping strategies, such as avoidance, substance abuse, or other equally harmful ones. (Leahy, 2018). To date, there are no studies that have analyzed these same relationships, although there exist precedent research that includes other interesting transdiagnostic variables. For example, Levin et al. (2012) found that psychological inflexibility mediated the relationship of psychological distress to alcohol-related problems, and Pedrelli et al. (2011) found a moderated relationship between depressive symptoms and daily alcohol consumption. Moreover, Devynck et al. (2019) found a strong positive association between repetitive negative thinking and alcohol use or alcohol-related problems. Negative urgency (propensity to engage in impulsive behavior while experiencing distress) also explains the association between anxiety symptomatology and both alcohol and cannabis use problems (Wolitzky-Taylor et al., 2016). Nonetheless, more studies are required to reach conclusive results in this field.

The effect of stress on alcohol consumption after controlling for psychological inflexibility as mediator and gender as moderator was significant for both men and women students. In other words, the mediation of psychological inflexibility between stress and alcohol consumption is positive and strong for both men and women, even higher in women. It could be explained because women reported significantly higher levels of both psychological inflexibility and stress than men students did. Likewise, Kheirabadi et al. (2021) and Barenz (2017) revealed that psychological inflexibility positively mediates the relationship between stress and substance abuse. However, to our knowledge, there are no investigations that have studied the relationships between these variables. Therefore, our study adds to the previous literature the influence of gender in the relationship between stress and psychological inflexibility, as transdiagnostic variables, in the consumption of alcohol among college students.

This transdiagnostic approach opens up new ways of assessing and classifying AUD, suggesting alternatives in the understanding of the processes involved, and provides a new theoretical foundation on the initiation and maintenance, as well as the clinical treatment and recovery of these disorders (Dalgleish et al., 2020). Overall, this novel emotional vulnerability model includes a set of key clinical factors underlying alcohol use and different emotional conditions (Leventhal and Zvolensky, 2015). However, to date, no research had yet examined the relationship between both transdiagnostic constructs (psychological stress and psychological inflexibility) and problematic alcohol consumption. There is still much to investigate henceforth to generate true innovations and avoid conceptual biases to deliver a transdiagnostic paradigm shift that can improve assessment protocols and clinical care (Fusar-Poli et al., 2019).

Several limitations of this study merit mention. Firstly, statistically significant differences might be sensible to the large size of the sample. In addition, results might be confound by university culture, since differences in alcohol consumption were reported between the three main Ecuadorian regions in men and women, as expected based on previous studies (CONSEP, 2014). Moreover, results of this study must be considered with caution since cross-sectional design limits the capacity to stablish causal relationships. Future studies would benefit from longitudinal design to further explore changes on psychological inflexibility, stress, and alcohol consumption over time. Finally, self-reported data may be subject to desirability.

Results of this study support psychological stress and psychological inflexibility as critical transdiagnostic variables related to increased rates of alcohol consumption among Ecuadorian college students. Furthermore, psychological inflexibility mediates the negative impact of psychological stress on alcohol consumption, with a higher degree among women. These findings contribute to the development of transdiagnostic comprehensive programs, which encompasses promotive, preventive, and treatment services, to alleviate the burden of alcohol, including gender differences, and to enrich the growing research on alcohol consumption in this population.

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

The studies involving human participants were reviewed and approved by MSP-DIS-2015-0088-O. The patients/participants provided their written informed consent to participate in this study.

PR and SV-G: conceptualization and funding acquisition. PR, CL-N, and RS-P: methodology and data curation, RS-P: writing—original draft preparation. PR and CL-N: writing—review and editing. All authors have read and agreed to the published version of the manuscript.

This study was funded by the Universidad Técnica Particular de Loja (Ecuador) and the National Council for the Control of Narcotic Drugs and Psychotropic Substances (CONSEP), grant number PROY.PSC.1055. Additional funding was provided by the European Union—Next Generation EU through the Grant for the Requalification of the Spanish University System for 2021–2023 at the Public University of Navarra (Resolution 1402/2021). The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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