Context: Dopamine has been implicated as an important neurotransmitter involved in regulating appetite and food intake by modulating the reinforcement of food via the meso-limbic circuitry of the brain. Several genes have been linked with the regulation of dopamine. Monoamine oxidase A (MAOA) modulates the metabolism of serotonin and dopamine, both of which are neurotransmitters involved in the regulation of appetite and food intake. The gene coding for MAOA contains a 30-bp tandem repeat (uVNTR) polymorphism in its promoter region that has been previously identified to be associated with energy balance behaviors and body mass index (BMI). The gene coding for dopamine receptor D4 (DRD4) contains a 16 amino acid (48-bp) repeat polymorphism that has been linked with food consumption and BMI. Lastly, the dopamine transporter gene (SLC6A3: Solute carrier family 6 – neurotransmitter transporter, dopamine – member 3) codes for a dopamine transporter protein (DAT) that mediates the active reuptake of dopamine from the synapse. The transport gene contains a 40-base variable number tandem repeat (VNTR) at the 3’ untranslated region (3’-UTR) that has been previously identified to be associated with variable levels of postsynaptic dopamines. Objective: Our goals were to investigate the population effects of the aforementioned functional polymorphisms on various types of food consumption (soda, fast food, snack, and ready to eat foods) and physical activity (exercise and TV watching), and to further explore gender differences and interaction effects with negative stressors. Methods: The analyses were conducted with data on genotypes and self-reported behavioral characteristics among 951 Chinese adolescents 11-15 years old living in Wuhan, China. Results: Males with the high-activity allele of MAOA had lower odds of increased soda intake (adjusted OR=0.63; 95% CI: 0.41-0.98, p=0.03) than those with low activity allele. Experience of negative stressors significantly strengthened the protective genetic effect on increasing odds of engaging in vigorous activity (adjusted OR for interaction=1.89 with 95% CI of 1.89-2.52, pvalue for interaction=0.04). Additionally, combined males and females with DRD4 variant had greater odds of engaging in vigorous exercise (adjusted OR=1.39; 95% CI: 1.01-1.86, p=0.03) and of increased soda intake (adjusted OR=1.33; 95% CI: 1.01-1.76, p=0.04) than those with the wild-type allele. Among females, wild-type carriers (no 2R or 7R allele) when exposed to negative stressors were significantly more likely to engage in vigorous exercise (adjusted OR=0.14, 95% CI: 0.047-0.43, p=0.000586). Lastly, combined males and females with the DAT variant had increased odds of watching TV (adjusted OR=1.59; 95% CI: 0.61-1.77) and decreased odds of consuming fast foods (adjusted OR=0.60; 95% CI: 0.38-0.95, p=0.030654) than those with DAT wild-type. Experience of negative stressors significantly weakened the protective genetic effect on the odds for fast food consumption (adjusted OR=0.30; 95% CI: 0.13-0.66, p=0.002639). Conclusions: Our findings confirm the genetic effects of the dopamine regulating genes polymorphisms on food consumption and physical activity, and provide new insights about interactions with negative stressors.

The research questions of this study explore, first, the general patterns of Internet access and engagement among Korean immigrant adolescents, and second, the relationships between the adolescents’ culture-specific online activities and their (a) Korean cultural orientation, (b) American cultural orientation, and (c) bicultural competence. The separate examinations of Korean and American cultural orientations and the consideration of bicultural competence are based on the bicultural model to immigrant’s cross-cultural adjustment, which asserts that cultural orientations to the host and home countries develop and operate independently. Both types of cultural orientation are considered to be multidimensional, involving five distinct processes: cultural identity, knowledge of cultural values and norms, knowledge of popular culture, language proficiency, and cultural social support. Finally, a number of different culture-specific online activities—i.e., email, social networking, entertainment media, and information seeking activities performed on both Korean-language and English-language websites—are considered based on the assumption that different activities will engage different types and levels of cultural orientations and bicultural competence. The research questions are addressed by analyses of data collected through a quantitative survey of 168 Korean immigrant teenagers residing in Texas. The findings of this study demonstrate that these young Korean immigrants are privileged and active users of the Internet. Their online engagement is influenced by common youth-oriented interests as well as by their cultural orientations toward Korean and American cultures. Specifically, different types of culture-specific online activities invoke different aspects of the adolescents’ Korean and American orientations. In particular, the multiple dimensions of American (vs. Korean) orientation are more commonly associated with culture-specific online activities in general, negatively predicting Korean-website activities while positively predicting English-website activities. Of the multiple dimensions, knowledge of popular culture is most commonly associated with culture-specific online activities, while language proficiency is least associated. Further, levels of engagement with culture-specific online activities differ across groups of differing levels of bicultural competence. Particularly, individuals who are biculturally competent across multiple cultural orientation dimensions experience more engaged and diverse online experiences within English-language websites. This study offers theoretical and methodological implications for research on youth and online media and research on immigrants’ cross-cultural adjustment. / text

The current study used multi-wave data from the National Longitudinal Study of Adolescent to Adult Health to examine the existence of typologies of readiness for sexual intercourse and contraception among a nationally representative sample of adolescents aged 15-18. Grounded in the theory of planned behavior, the current study used latent profile analyses to establish five profiles of sexual readiness based on adolescents' attitudes, subjective norms, and perceived behavioral control for sexual intercourse and contraception. Analyses were conducted cross-sectionally and longitudinally, and five classes were confirmed at each of two waves. The current study established and characterized four profiles of readiness for sexual behavior at both waves: “impulsive adolescents,” “precarious adolescents,” “well-controlled adolescents,” and “conservatively-reared adolescents.” Two separate fifth profiles also emerged: “hasty adolescents” at wave 1, and “unrestrained adolescents” at wave 2. Logistic regression of longitudinal data indicated that compared to “impulsive adolescents” at wave 1, “precarious” and “conservatively-reared” adolescents were significantly less likely to engage in sexual intercourse at wave 2, and “well-controlled” adolescents were significantly less likely to engage in casual sex. Wave 1 cross-sectional data indicated that “precarious” adolescents were less likely to have used contraception either at their first time or most recent time of sex, and all other profiles were more likely to have employed contraception than “impulsive” adolescents. Wave 2 cross-sectional analyses indicated that two profiles (“precarious” and “conservatively-reared”) were less likely to engage in sexual intercourse, and two profiles (“well-controlled” and “unrestrained”) were more likely to engage in sexual intercourse than “impulsive” adolescents. / text

Although about half of all rape victims are adolescents, the bulk of the research on sexual victimization is focused on college or community samples of adult women. As such, little is known about adolescent risk of sexual victimization. Adolescence is an important developmental phase in life, in which an individual undergoes major social and biological changes. These changes may make them more susceptible to environmental characteristics, such as family climate, compared to adults. Environmental factors may influence risk taking among adolescents, which may increase the risk of sexual victimization. The theory of social support can be useful in understanding why some young individuals are sexually victimized and others are not. Data for the analysis is derived from the National Longitudinal Study of Adolescent Health (Add Health). The current study uses the in-home interviews from Wave I, Wave II, and Wave IV of Add Health. The purpose of the study is to examine the relationship between social support, risky behavior, and sexual victimization. Specifically, whether risky behavior mediates the relationship between adolescent sexual victimization and social support will be examined.

Adolescence is a time associated with increased risk taking and peer relations. Research has shown that adolescents are more vulnerable to peer pressure compared to adults, leading to exacerbated risk taking. Preclinical research suggests that these findings may also be applicable to adolescent rodents, which find social interaction rewarding and are prone to risky behavior. There is, however, little research on the effect of social interaction on rodent models of risky decision-making. This thesis utilized social chambers, which consisted of adjacent operant chambers separated by wire mesh. Adolescent rats performed a risky decision-making task in which they had a choice between a small and large reward (associated with a mild footshock, which increased in probability across the session). Experiment 1 determined if the presence of peer altered performance on the task after stability. Experiment 2 determined if the presence of a peer altered performance on the task during acquisition. Results of Experiment 1 revealed no significant changes. Results from Experiment 2 revealed a significant increase in preference for the risky reward in the group of rats that had daily exposure to a social peer. These results provide evidence that social influence on risk taking can be modeled in rodents.

This study explored the effects of the Canterbury earthquakes of 2010 and 2011 on different areas of quality of life (QOL) for children and adolescents with disabilities. Using a survey developed from the Quality of Life Instrument for People with Developmental Disabilities – Short Version (QOL-PDD-SV) (Brown, Raphael & Renwick, 1997) and The World Health Organisation Quality of Life - (WHOQOL)-BREF, parents or caregivers were asked to identify what level of importance and satisfaction their child or adolescent placed on areas of QOL including physical health, psychological health - stress levels and coping ability, attachment to their neighbourhood, friends, family, leisure activities, community access and schooling. They were also asked to determine what level of impact the earthquakes had had on each area of their child or adolescent’s life and overall quality of life in the aftermath of the earthquakes. A total of 31 parents of 22 males and 9 females between the ages of 2.5 years to 19 years of age (mean age: 12.6 years) responded. The results were collated and analysis was run to measure for the effect of age, gender and geographical location. The results found that the earthquakes affected nearly every area of QOL for the children and adolescents. The biggest impact on the children’s psychological health and their ability to cope It was observed that younger children (<13) were more likely to record improved or lessened effects from the earthquakes in psychological health areas. However, the areas of social belonging and friendships were the least affected by the earthquakes. Female children were more likely to indicate higher scores for social belonging after the earthquakes. Many parents observed that their children developed improved coping skills over the earthquake period. The findings in this study offer a better understanding of how earthquakes can affect the quality of life children and adolescents with disabilities.

The primary aim of this research study is to examine how contextual and psychological variables interact on the development of Latina adolescents’ interests in science, technology, engineering, and math (STEM). The literature review starts with an overview of career interest development theories and an identification of key common factors. The major factors of parent socialization and the social constructions of gender and ethnicity are then discussed with particular emphasis on how they may influence interest development for middle school Latina students. This section concludes with an investigation into differences in access to school science and math resources, an environmental factor that also impacts development. The final section proposes a quantitative analysis that will address various questions raised in the literature review. The proposed study consists of correlations and linear regressions, controlling for background variables, as well as investigating interactions between identified factors. / text

The presence of stress is normative for individuals, and it is how one copes with stress that is important towards a person's well-being. In stressful situations, one's cognitive appraisal of and emotional reactions to a challenge are based on whether it is perceived as a threat to one's beliefs and goals. Mindfulness meditation training (MMT) is a set of coping strategies that has demonstrated beneficial effects for adults in reducing stress, enhancing wellbeing, and promoting cognitive efficiency. This procedure incorporates breathing techniques to regulate physiological responses and teaches the person to appraise moment to moment sensations, feelings and events as transitory, positive or neutral to assist in emotional regulation. In the past decade, research has suggested that MMT is appropriate and effective for children and adolescents, although most studies have been with clinical populations. The present study examined the relative effectiveness of MMT in stress reduction, and in promoting the mindfulness and well-being of adolescents enrolled in an International Baccalaureate (IB) program. Twelfth-grade students self-selected to participate in either an eight-week MMT course or to complete surveys as part of a no-treatment control group. Ratings for perceived stress, mindfulness, and well-being were collected from the MMT and the control groups at pre-intervention, post-intervention, and at one week prior to admission of high stakes IB exams. A repeated measures 2 X 2 ANOVA was conducted for each of the three scales. Within the repeated measures ANOVA, the interaction between the factor of treatment/no treatment and the within-subjects variable "point in time" (before training, after training, and prior to the exam) was found to be statistically significant. Subsequent post hoc testing showed that the significant interaction effects occurred only at pre-test for the three measures of perceived stress, mindfulness and well-being, indicating that the groups were very different to begin with. These findings were discussed with respect to the current literature on MMT. Future directions for research in this area were also discussed, as were the limitations of the study.

A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine.

Untreated depression has a detrimental effect in the lives of the adolescents suffering from this disorder. Depression is a multidimensional phenomenon that has been linked to biological, psychosocial and cognitive risk factors. Adolescents may be at risk for depression because adolescence is a time of physical, hormonal, emotional and intellectual changes. Depression may lead to impaired social and school performances and to poor physical health. In addition to a reduced quality of life, depression has also been linked to suicidal ideation and attempts. Suicide is the third cause of death in adolescents in the United States.The purpose of this practice inquiry was to conduct a critical review and synthesis of the literature on evidence-based treatment of unipolar depression in adolescents and to make recommendations for health care providers. This topic was chosen because of the high prevalence of depression in adolescents and because of the devastating effects of not treating this disorder.The methods used to synthesize the literature are described in the Guide for Literature Reviews by Cooper (1998). After the problem was identified, a literature search was conducted in PubMed, Cinahl, Psych Info, Complementary and Alternative Medicine and AMED. Next, the literature yielded 93 articles. The evidence from the literature was ranked according to the Oncology Nursing Society (ONS), Putting Evidence into Practice (PEP), Levels of Evidence scale. This system is an adaptation of the Rating the Quality of Evidence for Clinical Practice Guidelines developed by Hadorn and others (1996). Lastly, the recommendations for practice were made based on the ONS PEP, Weight of Evidence Classification Schema by Mitchell & Friese. Based on the evidence found in the literature, a guideline with the recommendations for practice was developed.The need for the treatment of adolescents with depression was supported in this synthesis of the literature. Future research is needed to explore treatment modalities tailored to the developmental, biological, psychosocial and cultural needs of adolescents and their families.