UMD Theses and Dissertations
Permanent URI for this collectionhttp://hdl.handle.net/1903/3
New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a given thesis/dissertation in DRUM.
More information is available at Theses and Dissertations at University of Maryland Libraries.
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Item INTERACTIONS BETWEEN SEROTONIN AND BEHAVIORAL SENSITIVITY TO ACUTE ALCOHOL EXPOSURE IN CRAYFISH(2021) Ho, Tawen; Herberholz, Jens; Neuroscience and Cognitive Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Social isolation has been found to correlate with an increase in alcohol consumption in humans. However, neurobehavioral and neurocellular mechanisms underlying interactions between alcohol and social isolation have been understudied. Prior work has shown that socially isolated crayfish exhibit lower behavioral and neural sensitivity to acute ethanol (EtOH) exposure than communally-housed conspecifics. Here we report an important role of the serotonergic system in mediating this socially-dependent effect. We found that depletion of serotonin (5-HT) from serotonergic neurons reduced behavioral sensitivity to EtOH, but the effect was more pronounced in communally housed animals. In addition, antagonizing 5-HT2β receptors also reduced EtOH sensitivity, and more strongly in group-housed animals, suggesting a possible down-regulation of 5-HT2β receptors in isolates. Pre-treatment with a selective serotonin reuptake inhibitor (fluoxetine) produced opposite modulatory effects, affirming the role of 5-HT in shaping the interactions between social experience and EtOH sensitivity. Thus, we show here, for the first time, that behavioral sensitivity to acute EtOH (i.e., intoxication) in crayfish is partially mediated by 5-HT, and our results suggest specific 5-HT receptor subtypes as possible targets for these interactions. This work might have relevance for studying the neurochemical mechanisms underlying the interplay between social history and alcohol sensitivity in other organisms. However, due to large variability in the experimental data and differences in sample sizes across conditions, the results should be considered preliminary, and future work will be aimed at increasing sample sizes and replication of results.Item The Effects of Marijuana Legalization on Adolescent Alcohol Consumption(2019) Montano, Ashley Nicole; Dugan, Laura; Criminology and Criminal Justice; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Among researchers, there has been a long-standing debate on the issue of whether alcohol and marijuana are used as substitutes or complements of one another. In other words, does the increased usage of one decrease the usage of the other (substitution) or does usage of both substances simultaneously increase (complements)? The primary purpose of this study is to identify whether a suggested substitution or complementary effect exists among adolescent drinking patterns following the recent emergences of increased marijuana legalization. To explore these effects, data is used from 38 different states included in the Youth Risk Behavior Surveillance System between the years 1995 and 2017. The primary analysis finds limited support for a substitution effect and no evidence of a complementary effect among adolescents. This study also includes a supplementary analysis providing implications for the direction of future research on the apparent relationship between alcohol and marijuana usage patterns.Item Sleep throughout the alcoholism recovery process: a mixed methods examination of individuals' experiences transitioning from an inpatient research facility providing rehabilitation treatment to the community(2015) Brooks, Alyssa Todaro; Beck, Kenneth; Public and Community Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Despite research establishing the relationship between sleep disturbances and alcohol use, there is no clear understanding or model for what occurs once individuals who seek inpatient alcoholism treatment are discharged from rehabilitation facilities and attempt to integrate back into their homes and communities. This study used a mixed methods approach to assess individuals' perceptions of and experiences with sleep throughout the process of alcohol rehabilitation and to explore associations between sleep-related beliefs/behavior, sleep quality, and relapse. The Social Cognitive Theory (SCT), which posits that personal factors, the environment, and human behavior exert influence upon each other through reciprocal determinism, was used as the underlying theory for this study. Constructs from the SCT were measured directly in this study using both quantitative and qualitative approaches in a convergent parallel design to study the following aims: a) to assess perceptions of and experiences with sleep during alcohol rehabilitation, b) to describe sleep patterns, perceptions, and beliefs among individuals who are alcohol-dependent throughout the transition from a clinical research facility providing rehabilitation treatment back to the community, and c) to assess whether sleep-related beliefs and/or behavior are associated with sleep quality or alcohol relapse. Data were collected from a cohort of clinical research participants enrolled on an inpatient alcohol treatment protocol (n=32). Sleep was assessed quantitatively and qualitatively within one week of discharge from the inpatient facility and again four to six weeks post-discharge. Results indicated a prevalence of sleep disturbances throughout the process of rehabilitation. Self-efficacy for sleep was associated with better sleep quality at both time points. Thematic analyses of interview transcripts yielded overarching themes of sleep-related beliefs/behavior, sleep environments, stress related to transitions, and self-medication. This study demonstrates a prevalence of sleep disturbances among individuals undergoing alcohol treatment and relationships between SCT constructs and sleep quality. The period of transition from inpatient to outpatient represents a time of change, thus future behavioral sleep intervention efforts in this population may benefit from addressing underlying sleep-related beliefs and behaviors to improve sleep quality and encourage healthy and sober living.Item Scale Development and Dimensionality Analysis of a Protective Behavioral Strategies Multi-item Scale for Use with College Student Drinkers(2008-06-17) Griffin, Melinda; Boekeloo, Bradley O; Public and Community Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Protective behavioral strategies (PBS) have been defined as self-control behaviors individuals practice prior to, during, and/or after drinking to limit consumption and/or the negative consequences. Although a multi-item PBS measurement scale has been used in the research literature, the psychometrics, reliability, and validity of the PBS scale needed further examination. This study examined the 1) dimensionality of the PBS scale for self-identified college student drinkers as well as for gender and race/ethnicity subgroups, 2) internal consistency and test-retest reliability of the PBS sub-scales, and 3) construct validity of the PBS sub-scales. College students who self-reported as recent alcohol users (n=320) on a web-based survey administered during fall semester of the 2006 academic school year comprised the study sample. Factor analysis was utilized to determine the underlying factor structure of 22 item PBS scale. Additionally, congruence of the factor structure among gender and racial sub-groups was examined by rotating the sub-groups' matrices via the Procrustes orthogonal method. Reliability analysis was utilized to determine the internal consistency of the PBS sub-scales. Separate multiple linear regressions were performed to determine the construct validity based on relationships between the PBS sub-scales and potential motivations (refusal self-efficacy, protection self-efficacy, drunkenness avoidance self-efficacy, alcohol abstinence expectations) and potential alcohol-related outcomes (multiple alcohol use items, negative consequences) while controlling for gender and race. Examination of the output from repeated factor analyses, Procrustes rotation, and reliability analyses resulted in a 2-factor solution with 17 items. Both PBS sub-scales (Planning and Execution) had acceptable internal consistency across all samples and acceptable test-retest reliability. Construct validity of the Execution PBS was fully supported whereas the Planning PBS was partially supported. Specifically, the Planning PBS sub-scale was highly correlated with protection and drunkenness avoidance self-efficacy as projected but not alcohol-related outcomes. The Execution PBS sub-scale was highly correlated as projected with refusal, protection and drunkenness self-efficacy, alcohol use, and negative alcohol effects. Special attention was given in this study to PBS construct validity considering potential PBS motivations and PBS scale dimensionality across gender and race subgroups. This study contributes to parallel research attempting to identify a definitive, standardized measure of PBS.Item Peer influence contexts of alcohol use among first-year college students: Investigating the roles of race, ethnicity, and gender through multigroup measured variable structural equation modeling(2006-12-18) Snyder, Kathryn Renee Baird; Komives, Susan R.; Hancock, Gregory R.; Counseling and Personnel Services; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The study purpose was to examine the contributions of peer context variables to the explanation of alcohol use of first-year college students by racial-ethnic group and by gender. Social norms theory and the theories of planned behavior, social identity/self-categorization, and status/status construction contributed constructs. Construct-related scores from sample survey responses demonstrated strong reliabilities ranging from .70 to .97. The following constructs provided measures for the study: Normative perception, subjective norm, affective attitude, cognitive attitude, social identity/self-categorization, status value, perceived behavioral control, intention and alcohol use. Normative perception and subjective norm were combined to create a single scale with stronger reliability than either had separately. Both cognitive and affective attitude were combined to create a single scale. Normative perception and attitude were measured the summer prior to college and in the fall; alcohol use was measured in the fall and in the spring. All other model variables were measured in the fall. Survey data were collected online in three waves and were from a representative sample (N=837) at a large state research institution with a predominantly White (65%) undergraduate student body. Rates of self-reported past month alcohol use and heavy episodic drinking of participants were comparable to those of similar samples in national and in-state studies. Applying multigroup measured variable structural equation modeling, the model explained between 60% of the variance in spring term alcohol use for Asian Pacific American students and 92% for African American/Black students. Data-model fit was acceptable (NFI, CFI > .95, SRMR < .08) for all groups in both analyses. Direct, indirect, and total effects of model variables were identified for each of five racial-ethnic groups in the study (African American/Black, Asian Pacific American, Latino/Latina American, White American, and Multiracial/Biracial American) and by gender for White men and White women. Tests of invariance demonstrated where specific paths in the model were significantly non-invariant (differed) and for which groups. Findings suggest the importance of pre-college intervention, the risk of increased alcohol misuse for first-year students, and the conditional effects of racial-ethnic group and gender.