In fact, the modeling approaches used in previous studies of alcohol consumption trajectories are specific instances of finite mixture models . This study has some limitations. First, we relied on self-reported alcohol consumption which is known to have some measurement error. Nonetheless, our use of a validated instrument , delivered by a computer assisted interview, has been shown to be a valid and reliable method to measure alcohol consumption, and a recent analysis of trajectories using AUDIT-C has shown that they are correlated with alcohol consumption biomarkers. Second, the time period for this study is prior to the widespread use of direct acting agents for HCV infection, and it is unknown how HCV cure may affect drinking over time. Third, this is a clinic-based study of PWH, which means our data collection is dependent on the health care process. While this may affect the quality of our measurements, this may increase the generalization of our results to the population of diagnosed and linked to care PWH. Also, we do not know what the drinking patterns of participants were prior to study start. It is possible that some of the people that did not drink at their first CASI who subsequently transitioned to moderate or alcohol misuse had prior misuse, which is an important predictor of subsequent alcohol use. In a recent study in this same cohort, vertical growing systems greater than 1/3 of current individuals reporting non-use had a prior alcohol use disorder. Fourth, we only considered predictors measured at baseline .
Previous research has shown the importance of considering longitudinal changes in some clinical factors such as depression or anxiety, which may be cause and consequence of specific alcohol consumption patterns. However, our study was descriptive in nature and we did not aim at making inferences about the causal direction of this association. Furthermore, our main analysis only presents the age-, race-, and site-adjusted associations. We believe this represents the clinical reality better than a multivariate model that adjusts for every other factor available, where associations may be harder to interpret. However, we include the fully adjusted multivariate model in the appendix for transparency. Finally, our study classifies all individuals with AUDIT-C scores between 3 or 4 to 12 in the same group . Recent studies have shown that people with AUDIT-C scores equal or above 8 have increased risk for mortality. Future studies with adequate sample size to examine trajectories among individuals in this group would provide greater insights about those with heavier alcohol misuse. Our study has important implications for the management of alcohol use in HIV clinical settings. First, given that trajectories of alcohol use do change, it is important to routinely screen all individuals for alcohol use, including those who report no or moderate use. Second, it is also important to ensure that individuals with alcohol use are screened for comorbid mental health and substance use disorders.
With the relatively high frequency of comorbid mental health and substance use among those with alcohol misuse, it may be important to develop bundled interventions for these comorbid conditions. Finally, with significant alcohol related morbidity and mortality among PWH, integration of evidence based alcohol interventions into HIV clinical settings is an important aspect of the primary care of PWH. Future studies must work to identify how best to implement these interventions at both the provider and the system-level.Substance use initiation greatly increases across adolescence . Youth with greater internalizing and externalizing problems tend to show high risk for substanceuse, and differences in the activation of to two key stress response systems—hypothalamic pituitary adrenal axis and emotion—have been related to both . However, limited research has examined whether differences in the biological and psychological responses to stress, with respect to changes in corThisol secretion and emotions following stressor onset and across a recovery period, relate to substance use among adolescents, especially those at heightened risk for substance use. The present study examined how differences in the stress response related to substance use in a sample of Mexican-origin youth growing up in a low-income region with high levels of adversity . Using a longitudinal study design, we tested whether differences in HPA axis reactivity and emotion and recovery to stress at age 14 were associated with use of alcohol, marijuana, and cigarette use by age 14 ; use of alcohol, marijuana, cigarettes, and vaping of nicotine by age 16; and onset of alcohol, marijuana, and cigarette use between ages 14 and 16. Finally, we tested whether associations between stress reactivity, stress, recovery, and substance use varied by poverty status and sex.
Substance use greatly increases during adolescence, as the percentage of students who have used an illicit drug doubles from 8th to 10th grade, and nearly half of students report using at least one substance by 12th grade . Although experimentation is common in adolescence, youth who use alcohol, tobacco, and marijuana earlier in adolescence are at higher risk for psychopathology and substance use disorders in adulthood . Previous research has also consistently found that use of alcohol and marijuana by ages 14 and 16 specifically are related to poorer adjustment and higher use later in adolescence and adulthood . Risk is particularly high for Latinx adolescents, who show higher lifetime use of varied substances by 8th grade and by 12th grade compared to White and Black youth, and tend to begin using cigarettes, alcohol, and other drugs at earlier ages than other ethnic minorities . Furthermore, prior research suggests that Mexican American adolescents, specifically, are more likely to have initiated substance use by the eighth grade than non-Latinx and other Latinx youth .People generally respond to stress by showing increased negative emotion, decreased positive emotion, and activation of the HPA axis, a biological system especially sensitive to social-evaluative stressors . Exaggerated emotion reactivity to stress has been related to poorer health . However, inability to mount a response or showing blunted reactivity to stress may suggest disengagement and has also been related to poorer well-being . Dampened reactivity and recovery following stress have also been related to poorer health including depression and externalizing problems . Individuals can show blunted rather than exaggerated stress reactivity and recovery for many reasons . Individuals who experience chronic or repeated stress may initially show heightened emotional and biological stress reactivity and recovery, and these responses may habituate and show a blunted profile over time . Therefore, whereas unpredictable, acute stressful life events may promote a profile of exaggerated reactivity to stress, living in adversity can serve as a chronic stressor and consequently can promote inflexibility of psychobiological systems over time, such that individuals are incapable of responding to acute stressors . Indeed, youth and adults who experience more adversity generally show blunted rather than enhanced corThisol and heart rate reactivity to acute stress , grow rack as well as reduced activation of neural regions involved in threat such as the amygdala . It has been posited that individuals who experience high levels of adversity may be inclined to disengage from stressors, which can attenuate psychobiological reactivity and recovery . Lastly, low reactivity may result from socialization from peers and parents .
For instance, youth who experience adversity may interact with deviant peers or bullies who prompt them to be less responsive to stress and may be socialized by parents to be less affected by daily stressors . Just as heavy substance use can dysregulate HPA axis function , dysregulation of the HPA axis may also contribute to substance use risk. Youth with blunted HPA axis reactivity to stress may lack physiological inhibitory control, such that they may be less inhibited by the social consequences of risk-taking compared to adolescents who show greater corThisol reactivity to stress . Alternatively, adolescents with chronic under arousal may be generally more inclined to pursue risky behaviors to promote physiological arousal . Youth may not show corThisol reactivity to a stressor because they are not sensitive to that stressor, or because they have already become elevated in anticipation of a stressor . That is, certain youth may be more responsive to the threat such that they already show elevated levels of corThisol prior to stress onset and consequently show no further elevation in corThisol thereafter. Both blunted corThisol reactivity and anticipatory corThisol have been associated with more frequent substance use later in adolescence, especially among youth with difficulties in emotion regulation . Dysregulation of HPA axis function may similarly promote risk for lifetime substance use during adolescence. Adolescents with higher basal corThisol had earlier onset of substance use, although corThisol was not assessed following stress , and blunted corThisol secretion in anticipation of a laboratory task has been linked to greater substance use in pre-pubertal boys . Given the potential for bidirectional associations between HPA axis function and substance use, longitudinal studies are needed to disentangle whether HPA axis reactivity to and recovery from stress relate to risk for substance use onset during adolescence. Specifically, it is well-established that heavy substance use—as opposed to substance use initiation or less frequent substance use—can dysregulate physiology , so researchers may be best positioned to examine the role of physiology on substance use risk during adolescence when youth are initiating substance use but have not yet engaged in heavy substance use. In addition to corThisol reactivity, emotion reactivity to stress may relate to substance use. There are several emotion-related risk factors for substance use and substance use disorders in both adults and adolescents, including greater negative emotions, emotional lability, and emotional dysregulation . Although it is well-established that emotions influence frequency of substance use among users, it remains unclear whether emotion reactivity to stress relate to adolescents’ risk for substance use initiation. Emotion reactivity to stress often includes increases in negative emotions of both high arousal and low arousal and decreases in positive emotion, and each form of emotional change can have unique implications for health . Youth with exaggerated and dampened stress reactivity and recovery with respect to emotion may be particularly at risk for earlier onset of substance use, especially for Mexican-heritage adolescents, who experience culturally-specific stressors . Therefore, research is needed to determine whether emotion reactivity to stress and recovery from stress is related to substance use and the emergence of substance use among these youth.The impact of stress reactivity and recovery on substance use during adolescence may vary by sex. Adolescents’ motivations for substance use differ by sex . Male youth tend to be more motivated to use substances for social enhancement whereas female adolescents are more motivated to use substances to cope with negative emotion and stress . Further, female adolescents show higher comorbidity between substance use and depression relative to male adolescents, suggesting that emotion and stress may be particularly tied to female adolescents’ substance use . Therefore, although male adolescents tend to show earlier and more frequent substance use relative to female adolescents , substance use may be particularly related to the stress response among female adolescents. Indeed, prior research regarding youth who have used substances by age 16 in this cohort of Mexican-origin adolescents has found that greater corThisol reactivity relates to earlier age of initiation of alcohol use for girls, whereas blunted corThisol reactivity was related to earlier initiation of marijuana use only for boys with less advanced pubertal status . It is critical to disentangle whether differences in stress reactivity and recovery precede substance use across the sexes. Poverty status may also moderate associations between responses to stress and substance for two reasons. First, early life adversity including poverty status has been found to influence psychobiology such that youth who experience early life adversity, including youth belowthe poverty line, tend to show profiles of blunted corThisol responses to stress . Because these youth are already at heightened risk for blunted corThisol responses, the association between these responses and substance use may be stronger among these youth. Second, poverty status may influence adolescents’ propensity for substance use. Youth below the poverty line may experience earlier exposure to substance use and substance related crime, more targeted marketing of substances, and lower parental involvement . They may also be more motivated to use substances for reasons beyond stress, such as due to boredom, sensation seeking, and pursuit of enhancing effects in order to compensate for a lack of pleasurable substance-free daily activities .