At the age of 13, the 2:1 ratio becomes evident. It entails the fact that after puberty, twice as many females as compared to males suffer from depressive episodes. Much research has been conducted to highlight key contributing factors that aid in the onset and the timing of the 2:1 ratio. Many researchers emphasize hormonal influences and the onset of puberty as key contributors, with theories such as the gonadic theory andthe interactional hypothesis both highlighting the role of hormones in the existence and the emergence of the 2:1 ratio during adolescence. Furthermore, a large variety of researchers emphasize females increased stress sensitivity and stress reactivity as key contributors to the 2:1 ratio. Critically, research concerning hormonal- and stress-related factors will be included. However, an additional focus will be on neurodevelopmental sex differences. This, as brain-based sex differences have been paid too little attention in theories and models concerning the emergence of the 2:1 ratio during adolescence. Results from research conducted to unravel the mystery of sex differences within the adolescent brain emphasize the impact of sex hormones on the maturational sexual differentiation occurring within the adolescent brain. It has been hypothesized that increases in female adolescent depression might occur in accordance with upsurges in peripheral estrogen levels, during puberty. This seems to suggest that there is an interaction between the effects of circulating ovarian hormones in relation to both sexual differentiation in brain organization and depression susceptibility. Hence, the point of this essay is to delineate key contributing factors that potentially govern the existence and onset of the 2:1 ratio during adolescence by emphasizing the areas of (a) sex-based neurodevelopmental factors, (b) hormonal factors and (c) stress-related factors.

Depression in adolescence is a major health problem, associated with poor psychological function and key risk factors both for later illness and suicidal behaviours. The antidepressant fluoxetine is commonly used in this population and it is shown to have a favourable benefit-to-risk profile. However, controversy still exists about the use of antidepressants in young people and there is little research focusing on underlying mechanisms of wanted and unwanted actions in this group. This doctoral thesis aims to investigate, for the first time, the acute effects of fluoxetine on emotional processing, using a combination of behavioural and neuroimaging techniques. The aim is to achieve a greater understanding of the mechanisms underlying fluoxetine use in depressed adolescents, in light of differences seen in their clinical presentation and response to antidepressant drugs. In the first study (Chapter Two), a single dose of fluoxetine was shown to decrease the recognition of anger in a sample of young adult volunteers, an effect not previously seen in acute studies of older participants. This effect may be particularly relevant for the treatment of adolescent depression, in which symptoms of anger and irritability are often prominent. Beyond this, fluoxetine was shown to increase the recognition of positive vs. negative facial information, and also exerted an anxiolytic-like influence, eliminating the emotion-potentiated startle effect. However, no influence was seen in measures of attentional vigilance to threat. In an attempt to overcome methodological limitations of this study, a paradigm was developed that is particularly sensitive to the detection of automatic biases towards threatening information (Chapter Three). Chapter Four describes a neuroimaging study with depressed adolescents, in which a single dose of fluoxetine was found to reduce amygdala activity in response to anger. Early changes in amygdala activity to fear correlated with decreased symptoms of anxiety and depression in the first 7-10 days of treatment. Chapter Five explores the effects of acute fluoxetine in a sample of high trait anger males. This study replicated the finding that fluoxetine acts to increase the recognition of positive information, whilst showing preliminary evidence for a reduction in attentional vigilance to angry faces. Overall, fluoxetine was found to decrease the processing of anger across studies. This effect was seen alongside a broader influence on positive vs. negative information and anxiolytic-like properties. Together, these results indicate that fluoxetine has direct effects on processes that are especially relevant to adolescent depression and suggest a potential cognitive mechanism for the efficacy of this particular antidepressant in adolescent patients.

Manualized, evidence-based treatments (EBTs) for children are being increasingly incorporated in community mental health clinics. Yet, providers hold concerns about the appropriateness of manuals for community populations, as suggested by the research of Jensen-Doss, Hawley, Lopez and Osterberg. Such concerns could lead them to adapt EBTs in the field, potentially diminishing or increasing their effectiveness. Therefore, it is striking how little is known about provider-level manual adaptation in community settings. The present study investigated the extent to which therapists mandated to use a manualized EBT adapt the treatment in the field, including patterns, predictors and outcomes of adaptation. A typology of provider-level manual adaptation was created to describe sessions double-dipped (i.e., repeated), skipped, or flipped (i.e., delivered in reverse order). Patterns of manual adaptation used by a sample of 38 community therapists treating 288 depressed youths with Lewinsohn and colleagues? Adolescent Coping with Depression course (CWD-A) were described. Hierarchical Linear Modeling was used to identify which client and therapist characteristics predict manual adaptation, and whether adaptation is associated with greater improvement or worsening in youths? therapy outcomes. Adaptation was widespread and largely unsystematic, with no significant client predictors of repeats or flips. Sessions were skipped more often for youths belonging to families with higher income and youths with greater pre-treatment symptom severity, but less often for Hispanic and Asian youths relative to Caucasians. A significant portion of variability in adaptation was attributable to therapists, who showed habits in manual adaptation: therapists with more years of experience working at the clinics double-dipped sessions more often, and Hispanic therapists flipped sessions much less often than Caucasian therapists did. Finally, adaptation was significantly related with outcomes, such that doubledips were associated with worsened symptom severity, skips were associated with improved symptom severity, and flips were associated with worsened functioning. Given that these data suggest manualized EBTs are likely to undergo vast adaptation in community settings, and that such adaptation is related to client outcomes, further research is necessary to better inform practitioners about when each type of manual adaptation may be appropriate. Practical implications for implementation efforts are discussed.

The inclusion of racial/ethnic minorities in treatment outcomes trials for children and adolescents with depression and anxiety is essential, particularly given the assumption, required by the NIH, that racial diversity is important to the generalizability of clinical trial outcomes. A search for randomized clinical trials on the treatment of child and adolescent depression and anxiety was conducted using the Medline and Psychinfo databases. These were then reviewed to determine whether race or ethnicity were 1) factored into recruitment strategies; 2) represented in the trial sample; and 3) included in moderator analyses to determine the extent to which they may influence trial outcomes. 37 original and 13 follow-up trials were identified (total N = 3330). None identified strategies for targeted recruitment of racial/ethnic minorities. Six did not report race. All minority groups except for Native Americans are underrepresented as compared to 2000 US Census figures; however, only one study reported Native Americans as participants. Overall, 67% of the sample was Caucasian, 26% minority, and 6% unreported. There was no trend in minority representation by year. Most studies reviewed do report the ethnic breakdown of their sample population, although methods vary. Six studies, three original and three follow-up, explored the ethnicity as a moderator. Without an increased presence of minorities in clinical trials, it is unclear that the results of these studies can reliably generalize to a diverse population. The importance of studies in minority samples becomes apparent, as does the need for a greater emphasis on recruitment.

Despite consistent evidence that adolescent girls are at greater risk for developing depression than adolescent boys (Ge, Lorenz, Conger, & Elder, 1994; Nolen-Hoeksema, 1987, 1990; Weissman, Leaf, Holzer, Myers, & Tischler, 1984), and that women continue to predominate among depressed adults throughout the lifespan (Kessler, McGonagle, Swartz, Blazer & Nelson, 1993), few studies have examined the etiologic risk factors that predict depression for adolescent girls using a prospective design or examined differential processes of risk in a sample of adolescent girls and boys. Furthermore, although a number of variables have been implicated as risk factors for depressive symptoms or onset of depression among adolescents, some methodological limitations exist. The objective of this research was to examine a set of risk factors suspected to predict depression in adolescents, and to test whether gender moderates these relations. Secondly, this study examined a set of risk factors proposed by the gender additive model of depression (Stice et al., 2000; Stice & Bearman, 2001) that attempts to partially explain the increased prevalence of depressive symptoms in adolescent girls compared to boys. Finally, exploratory classification tree analyses tested for interactions between risk factors that might signal differential pathways to depression. This research provides insight into the etiology of adolescent depression as well as the disparate rate of depression among adolescent girls versus boys, and also provides direction for identifying high-risk individuals and developing effective prevention programs. / text

Typescript. Includes vita and abstract. Includes bibliographical references (leaves 117-133). Also available online in Scholars' Bank; and in ProQuest, free to University of Oregon users.

Ethnic identity is an essential component of youths' sense of self and is influenced by social relationships and experiences. Despite the large amount of time adolescents spend in the school environment and with their peers, little is known about the influence of the overall school context on ethnic identity development. This study examined the direct and indirect effects of sixth grade school context (defined by negative peer relationships and school environment) on ethnic identity development and depression in ninth grade. Using cross-lagged analysis, the bidirectional impact of discrimination experiences on ethnic identity development was also explored. These relationships were also examined separately for European American youth, youth of color with one ethnicity, and multiethnic adolescents. For all adolescents, less negative peer relationships were related to higher ethnic identity level. Ethnic identity was also positively associated with later adolescent depression. In addition, school environment was related to ethnic identity development for European American and adolescents of color; for youth of color with one ethnicity, ethnic identity also predicted later depression levels. School context was not found to be associated with ethnic identity development for multiethnic adolescents, although negative relationships were related to higher depression levels for this group. Finally, the cross-lagged model of ethnic identity and discrimination suggested no bidirectional influence between these two variables. This study supports existing studies on the importance of ethnic identity on adolescent development. It also provides much needed knowledge of how the school context contributes to adolescent ethnic identity and depression. Furthermore, these findings contribute to the growing body of literature on the developmental trajectories of multiethnic adolescents. Findings from this study have implications for intervening at the school level. Promoting cultural sensitivity among students and staff can decrease negative peer interactions (e.g., bullying) and other negative social experiences, thereby decreasing the risk of poor academic and psychological outcomes for adolescents at risk of experiencing adversity.

This study examined links between adolescent depressive symptoms, actual pubertal development, perceived pubertal timing relative to one’s peers, adolescent-maternal relationship satisfaction, and couple sexual behavior. Assessments of these variables were made on each couple member separately and then these variables were used to predict the sexual activity of the couple. Participants were drawn from the National Longitudinal Study of Adolescent Health (Add Health; Bearman et al., 1997; Udry, 1997) data set (N = 20,088; aged 12-18 years). Dimensions of adolescent romantic experiences using the total sample were described and then a subsample of romantically paired adolescents (n = 1,252) were used to test a risk and protective model for predicting couple sexual behavior using the factors noted above. Relevant measures from the Wave 1 Add Health measures were used. Most of the items used in Add Health to assess romantic relationship experiences, adolescent depressive symptoms, pubertal development (actual and perceived), adolescent-maternal relationship satisfaction, and couple sexual behavior were drawn from other national surveys or from scales with well documented psychometric properties. Results demonstrated that romantic relationships are part of most adolescents’ lives and that adolescents’ experiences with these relationships differ markedly by age, sex, and race/ethnicity. Further, each respective couple member’s pubertal development, perceived pubertal timing, and maternal relationship satisfaction were useful in predicting sexual risk-promoting and risk-reducing behaviors in adolescent romantic couples. Findings in this dissertation represent an initial step toward evaluating explanatory models of adolescent couple sexual behavior.

No description available.

Unipolar depression, estimated to be the leading contributor to burden of disease in middle- and high-income countries, often has an onset in adolescence. The disorder is associated with substantial role impairment and is highly recurrent. This raises questions about both subsequent mental health and social outcome. In order to shed light on this, a community sample of adolescents with depression and non-depressed peers was followed-up after 15 years. In 1991-93, first-year students in upper secondary school (age 16-17) in the town of Uppsala, Sweden, were screened for depression. Adolescents with positive screening and selected peers with negative screening (n=631 in total) were assessed regarding mental health, social situation, and personality. At around age 31, the participants were followed-up in both national registers (n=609) and personal interviews (n=409). Outcome regarding social factors, mental health, and personality was assessed. At follow-up, the former depressed adolescents had completed higher education to a lesser extent than the former non-depressed adolescents. The females with adolescent depression were also at increased risk of subsequent abortion, divorce, single parenthood, and partner violence. Characteristics associated with depression in adolescence (such as poor school performance and disruptive disorders) seemed to contribute to the poor outcome in the social domain. Regarding adult mental health, long-term depression in adolescence was associated with a particularly poor outcome. Compared to adolescents with shorter episodes of depression, those with long-term depression were more likely to report recurrent depression, suicidal ideation, and a range of other mental disorders in adulthood. Measures of personality traits related to neuroticism (a tendency towards negative emotionality) were elevated during ongoing depression and anxiety disorders, but were normalized with remission. However, repeated depressive episodes seemed to leave the individual more vulnerable to stress. It is now important to assess if early treatment can alter the poor outcome depicted in this thesis. Since social adversity, educational difficulties, and interpersonal problems accompany the depressive disorder from adolescence onward, it should also be investigated if interventions aimed at such contextual factors can prevent recurrence and improve quality of life.