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Open Access Publications from the University of California

Scholarly Works (22 results)

  • Thesis
  • Peer Reviewed
UC Irvine Electronic Theses and Dissertations (2021)

Early drug use might to lead to drug addiction; the earlier individuals begin to engage in risky drug use, the more likely they are to engage in later drug abuse. Therefore, early intervention is warranted. This study explored individual differences in drug use tendencies in young and healthy adults. Specifically, I examined how self-reported emotion regulation (ER) difficulties and inhibition abilities, as indexed by resting heart rate variability (HRV), might predict risky drug use tendencies in young adults. I further considered these associations stratified by women and men. Novel results showed self-reported (or perceptions of) difficulties in ER were associated with higher drug usage in the full sample and this association was significantly stronger in women than men. Among the six different facets of ER difficulties, only those related to impulse control difficulties and limited access to ER strategies were most related to risky drug usage in women but not men. The other four facets of ER difficulties were not significantly different between men and women. An indirect association was found between resting HRV and drug use, mediated by self-reported difficulties in ER, particularly in women. Overall, results indicate that lower HRV and difficulties in ER indirectly and directly, respectively, predict risky drug use in women. These data are in line with research suggesting women might engage in risky drug use primarily for stress regulation while men might engage in risky drug activity irrespective of both resting HRV and difficulties in ER. Clinical implications are discussed.

    Cover page: Gender Differences on the Relationship among Resting Heart Rate Variability, Self-Reported Drug Abuse, and Difficulties in Emotion Regulation
    • Thesis
    • Peer Reviewed
    UC Irvine Electronic Theses and Dissertations (2023)

    Higher self-reported rumination, a common form of trait perseverative cognition, is linked with lower resting heart rate variability (HRV), which indicates poorer cardiac function and greater disease risk. A prior meta-analysis and systematic review indicates that in samples with fewer European Americans, the association of rumination with both heart rate and blood pressure was stronger. Thus, trait rumination may be more strongly associated with HRV among ethnically minoritized populations, but few studies exist. The current study therefore investigated whether differences in the association of self-reported rumination with resting HRV varied by ethnicity in a sample (N = 513; Mage = 19.41; 226 Women) of self-identified African Americans (n = 110), Asian Americans (n = 84), and European Americans (n = 319). Participants completed a 5-min baseline period to assess resting HRV, followed by the Ruminative Responses Scale, which contains three facets of rumination including brooding, depressive, and reflective rumination. On average, Asian Americans reported higher levels of rumination relative to European Americans. African Americans had higher average HRV than Asian Americans. Adjusting for covariates, higher self-reported rumination was significantly associated with lower HRV in both African and Asian Americans, but not significantly so in European Americans. This finding was consistent for brooding and reflective, but not depressive rumination. Overall, this study lends insight into a psychological mechanism – rumination – that may impact health disparities among ethnically minoritized individuals, contributing to an understanding of how stress gets under the skin among such populations.

      Cover page: Multi-Ethnic Variation in the Ties That Bind Rumination and Heart Rate Variability: Implications for Health Disparities
      • Thesis
      • Peer Reviewed
      UC Irvine Electronic Theses and Dissertations (2024)

      This dissertation investigates the relationship between resting heart rate variability (HRV) and substance use, including the potential moderating roles of gender and race. Study 1 analyzes data from the Midlife in the United States Study (MIDUS) to examine cross-sectional associations between resting HRV and substance use, exploring potential gender differences and mediation effects involving emotion regulation (ER). Results indicate that men reported higher emotion control, alcohol consumption, and cigarette smoking compared to women. Higher resting HRV was associated with increased alcohol consumption, particularly in women, while no significant link was found between resting HRV and cigarette smoking. Mediation and moderation models did not yield significant findings. Study 2 utilizes data from the Augusta Heart Study to examine associations between resting HRV in late adolescence and substance use in early adulthood, again while considering gender and race. Results show that men and European Americans used more substances than women and African Americans, respectively. However, resting HRV did not predict substance use. Among African Americans, the slope between resting HRV and cigarette smoking was more positive in women than in men. These findings suggest that resting HRV may not be a particularly strong predictor of substance use but could still hold relevance in specific contexts or subgroups. Further research is needed to explore the complex interplay of factors influencing substance use behaviors. This dissertation highlights the importance of understanding various motivations for substance use and emphasizes the need for ongoing research targeting individualized treatments based on marginalized identities.

        Cover page: Resting Heart Rate Variability and Self-Reported Substance Use: An Emphasis on Potential Gender and Racial Differences
        • Article
        • Peer Reviewed
        UC Irvine Previously Published Works (2018)
        OBJECTIVE: Studies of sex differences in heart rate variability (HRV) typically have not accounted for the influence of family history (FH) of cardiovascular disease (CVD). This study evaluated sex differences in HRV response to speech stress among men and women (age range 30-49 years) with and without a documented FH of CVD. METHODS: Participants were 77 adults (mean age = 39.8 ± 6.2 years; range: 30-49 years; 52% female) with positive FH (FH+, n = 32) and negative FH (FH-, n = 45) of CVD, verified with relatives of participants. Cardiac activity for all participants was recorded via electrocardiogram during a standardized speech stress task with three phases: 5-minute rest, 5-minute speech, and 5-minute recovery. Outcomes included time domain and frequency domain indicators of HRV and heart rate (HR) at rest and during stress. Data were analyzed with repeated measures analysis of variance, with sex and FH as between subject variables and time/phase as a within subject variable. RESULTS: Women exhibited higher HR than did men and greater HR reactivity in response to the speech stress. However, women also exhibited greater HRV in both the time and frequency domains. FH+ women generally exhibited elevated HRV, despite the elevated risk of CVD associated with FH+. CONCLUSIONS: Although women participants exhibited higher HR at rest and during stress, women (both FH+ and FH-) also exhibited elevated HRV reactivity, reflecting greater autonomic control. Thus, enhanced autonomic function observed in prior studies of HRV among women is also evident among FH+ women during a standardized stress task.
          Cover page: Sex and family history of cardiovascular disease influence heart rate variability during stress among healthy adults.
          • Article
          • Peer Reviewed
          UC Irvine Previously Published Works (2021)
          BACKGROUND: Women with chronic pelvic pain (CPP) have poor cardiovagal modulation. It is unclear whether this finding reflects a broader abnormality across many systems such as gastro-vagal modulation. AIM: To determine if maladaptive cardiovagal activity in females with CPP is accompanied by maladaptive gastric myoelectric activity. METHODS: A total of 36 health controls (HC) and 75 CPP underwent supine (10 min), then upright (tilted 70° head up; 30 min), and back to supine (10 min) positions. High-frequency heart rate variability (HF-HRV; 0.15-0.4 Hz) was measured as an index of cardiovagal activity. Cutaneous electrogastrography (EGG) assessed gastric myoelectric activity pre- and during-upright tilt. EGG measures from 16 HC and 31 CPP patients were available for analysis and included relative percentage of gastric activity within the normal (2-4 cpm) and tachygastria (4-10 cpm) ranges, plus ratio of normal/tachygastria. RESULTS: HF-HRV was lower in CPP individuals at all time points (each p < .05). CPP individuals showed lesser decrease in HF-HRV from supine to upright, and poorer HF-HRV recovery from upright back to supine (F[1, 106] = 4.62, p = .034). HC showed increase in tachygastria activity (t[15] = -2.09, p = .054) while the CPP group showed no change in tachygastria activity from pre-upright to upright (t[30] = -0.62, p = .537). CONCLUSIONS: Individuals with CPP going from supine to upright demonstrate an impairment in both tachygastria and the parallel decrement in HRV. These results support the hypothesis of a generalized blunting in the physiological modulation in CPP individuals affecting both cardiovascular and gastric systems.
            Cover page: Does maladaptive cardiovagal modulation extend to gastric modulation in women with chronic pelvic pain?
            • Article
            • Peer Reviewed
            UC Irvine Previously Published Works (2022)

            Rationale

            Coronavirus (COVID-19) disproportionately affects people of color (e.g., Black and Latinx individuals) in the U.S., increasing their morbidity and mortality relative to White people. Despite this greater threat to their well-being, the mental health impact of COVID-19 on people of color remains poorly understood. Perseverative cognition (PC; i.e., excessive worry and/or rumination), is a common psychological response to such threats that independently associates with poor mental and physical health.

            Objective

            To examine patterns of PC across race/ethnicity when the COVID-19 pandemic began.

            Methods

            This study surveyed 6,514 respondents from the NORC AmeriSpeak panel, a probability-based representative national sample of U.S. adults between 3/18/20-4/18/20. We employed traditional statistical analyses and natural language processing of open-ended data to examine pandemic-related worries.

            Results

            Weighted regression analyses with relevant covariates revealed group differences across specific domains of COVID-related worry. Relative to White respondents, Hispanic/Latino respondents reported more worries about social disarray, meeting basic needs, experiencing economic impacts, obtaining healthcare, and contracting COVID-19. Black respondents reported more worry about economic impacts relative to Whites. Additional group differences in worry emerged in open-ended data: Black respondents perseverated about death from COVID-19, whereas Hispanic/Latino respondents reported concerns about COVID-19 spread, and people refusing to uphold mitigation mandates. In contrast, White respondents expressed worry over compromised immune systems and economic collapse.

            Conclusions

            Results identify significant group differences in COVID-19 related PC, suggesting that people of color faced greater threat to mental well-being at the onset of the pandemic, and may be at greater risk for downstream PC-related physical health consequences.
              Cover page: Racial and ethnic differences in perseverative cognition at the onset of the COVID-19 pandemic
              • Article
              • Peer Reviewed
              UC Irvine Previously Published Works (2025)
              BACKGROUND: Cardiovascular disease (CVD) remains a key cause of mortality worldwide. Prior work has found that the association between stress and cardiovascular outcomes is moderated by emotion regulation (ER) and expressive suppression (i.e., emotion inhibition), which is linked with adverse outcomes (i.e., inflammation) in Western (Americans) but not Eastern (Japanese) populations. Existing cultural differences in biological stress responses and suppression use suggest that these factors may have different implications for CV outcomes. OBJECTIVE: We address this gap in the literature by examining if ER differentially moderates the relationship between stress and CVD risk between Japanese and American adults. METHOD: Participants were from the Midlife in Japan and Midlife in the United States studies and had complete biomarker and psychological data (Japanese: N = 315, M age = 59.22, 149 females; Americans: N = 524, M age = 51.98, 291 females). Stress was indexed using the perceived stress scale. Trait suppression and reappraisal were indexed using the Emotion Regulation Questionnaire. CVD risk was indexed using a composite score of body mass index, C-reactive protein, interleukin-6, systolic blood pressure, and high-density lipoprotein cholesterol ratio. RESULTS: Adjusting for age, sex, education, tobacco, alcohol, and prescription medication use, linear regressions revealed robust cultural differences among those with high suppression (r = -0.10 [-0.19, -0.01]). Higher stress was linked with higher CVD risk in Americans regardless of the level of reappraisal or suppression (rs > 0.11, ps < 0.07). In contrast, among Japanese with high suppression, higher stress was associated with lower CVD risk (r = -0.09 [-0.23, 0.05]). Higher stress was associated with greater inflammation among Japanese with lower suppression (r = 0.10 [-0.07, 0.28]). CONCLUSIONS: Consistent with prior work, these findings suggest that adaptive ER moderates the association between stress and CVD risk, and that suppression may not be universally maladaptive. Results emphasize the importance of considering cultural context when assessing the impact of emotion suppression on health, which may help explain differences in CVD outcomes between individuals from Eastern and Western populations.
                Cover page: Emotion suppression differentially moderates the link between stress and cardiovascular disease risk in Japanese and Americans.
                • Article
                • Peer Reviewed
                UC Irvine Previously Published Works (2019)
                Objective: Black Americans (BAs) are at an elevated risk for morbidity and mortality in comparison to White Americans (WAs). Racial stressors are a common occurrence in American culture and is theorized to contribute to these disparities. When race-focused, stereotype threat (ST) is considered to be a factor that is detrimental to health in BAs; however few studies have directly investigated the impact of a ST manipulation on physiological function. Furthermore, it is proposed that racial stressors such as ST may have prolonged effects when more likely to perseverate (e.g. rumination) over the stressor and thus, those with greater trait perseveration may be more affected by ST. We sought to explore the impact of ST and trait perseveration on changes in vagus nerve activity - an indication of adaptive psychological and physiological well-being - as indexed by vagally mediated heart rate variability (vmHRV). Design: Forty-three (24 females, mean age of 20, standard deviation of 3 years) apparently healthy BA individuals were randomly assigned to one of three experimental conditions in which they received either implicit (subtle), explicit (blatant), or no ST priming (control condition), prior to completing a cognitive task. Resting vmHRV was assessed both at baseline (pre-task) and recovery (post-task). Results: BAs in the explicit ST condition exhibited the greatest decrease in vmHRV in comparison to the control group from pre- to post-task. BAs with moderate to high levels of trait perseveration showed the greatest decrease in vmHRV from pre- to post-task in comparison to those with lower levels of trait perseveration and BAs in the control group. Conclusion: These data suggest that racial ST, especially when explicit and coupled with trait perseveration, can decrease vagal activity, as indexed by decreased vmHRV, which when experienced frequently can have significant consequences for health and longevity in BAs.
                  Cover page: Stereotype threat, trait perseveration, and vagal activity: evidence for mechanisms underpinning health disparities in&nbsp;Black Americans.
                  • Article
                  • Peer Reviewed
                  UC Irvine Previously Published Works (2021)
                  Background: A paradoxical profile of greater elevated sympathetic vasoconstriction (increased total peripheral resistance, TPR) and increased vagally-mediated heart rate variability (HRV) -the so-called Cardiovascular Conundrum- has been reported in African Americans (AAs) both at rest and in response to orthostasis. Whereas some authors have attributed this pattern to genetic factors, others have pointed to the potential role of coping with repeated racial discrimination. Objective: To disentangle between these alternative explanations, we have examined the hemodynamic profile of another population that is likely to be exposed to episodes of discrimination, i.e., sexual minorities. Methods: The first study was conducted on a sample of AAs and European Americans (EAs) with the aim of replicating previous results on the Cardiovascular Conundrum. In the second study, lesbian, gay, and bisexual (LGB) people, matched by age and sex with heterosexual participants, underwent a hemodynamic and autonomic assessment at rest and during an emotional (in the experimental group, both LGB-related and non LGB related), and a cognitive stressor. Results: The first study confirmed a pattern of higher resting HRV, paired with higher TPR, in AAs compared to EAs. In the second study, compared to heterosexuals, the LGB group showed the Cardiovascular Conundrum pattern, characterized by greater HRV and higher TPR at baseline and a more vascular hemodynamic profile and prominent compensation deficit in response to both tasks, and particularly during the LGB-related emotional task. However, in LGB only, the vascular response was negatively correlated with perceived discrimination. Conclusion: Present preliminary results are discussed in terms of maladaptive physiological consequences of exposure to chronic stress and the chronic use of dysfunctional emotion regulation strategies such as suppression.
                    Cover page: The Cardiovascular Conundrum in Ethnic and Sexual Minorities: A Potential Biomarker of Constant Coping With Discrimination.Creative Commons 'BY' version 4.0 license
                    • Article
                    • Peer Reviewed
                    UC Irvine Previously Published Works (2017)
                    The perseverative cognition hypothesis (PCH) posits that perseveration, defined as the repetitive or sustained activation of cognitive representations of a real or imagined stressor, is a primary mechanism linking psychological (or stress) vulnerability with poor health and disease. Resting vagally mediated heart rate variability (vmHRV) is an important indicator of self-regulatory abilities, stress vulnerability and overall health. Those with lower resting vmHRV are more vulnerable to stress, and thus more likely to engage in perseverative cognition and experience subsequent negative mental health outcomes such as anxiety. Recent research suggests that rumination-one of the core mechanisms underlying perseveration-is a construct containing (at least) two maladaptive (depressive and brooding) and one adaptive (reflective) types of rumination. However, to date, research has not examined how the association between resting vmHRV may differ between these three facets of rumination, in addition to these facets mechanistic role in linking lower resting vmHRV with greater trait anxiety. The current cross-sectional study explores these relationships in a sample of 203 participants (112 females, 76 ethnic minorities, mean age = 19.43, standard deviation = 1.87). Resting vmHRV was assessed during a 5-min-resting period using an Electrocardiogram (ECG). Both trait rumination (including the three facets) and anxiety were assessed via self-report scales. Significant negative associations were found between resting vmHRV and maladaptive, but not adaptive, forms of perseveration. Similarly, mediation analyses showed a significant indirect relationship between resting vmHRV and anxiety through maladaptive, but not adaptive, facets of rumination. Our findings support the PCH such that those with stress vulnerability, as indexed by lower resting vmHRV, are more likely to engage in maladaptive perseverative cognition and thus experience negative outcomes such as anxiety. Our data also lend a novel outlook on the PCH; resting vmHRV is not related to reflective rumination and thus, this facet of perseveration may be a neutral, but not beneficial, factor in the link between stress vulnerability and psychological well-being.
                      Cover page: Resting Heart Rate Variability, Facets of Rumination and Trait Anxiety: Implications for the Perseverative Cognition Hypothesis.Creative Commons 'BY' version 4.0 license
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