Depression from childhood into late adolescence: Influence of gender, development, genetic susceptibility, and peer stress.

Depression is a debilitating mental illness with clear developmental patterns from childhood through late adolescence. Here, we present data from the Gene Environment Mood (GEM) study, which used an accelerated longitudinal cohort design with youth (N = 665) starting in 3rd, 6th, and 9th grades, and a caretaker, who were recruited from the general community, and were then assessed repeatedly through semistructured diagnostic interviews every 6 months over 3 years (7 waves of data) to establish and then predict trajectories of depression from age 8 to 18. First, we demonstrated that overall prevalence rates of depression over time, by age, gender, and pubertal status, in the GEM study closely match those trajectories previously obtained in past developmental epidemiological research. Second, we tested whether a genetic vulnerability-stress model involving 5-HTTLPR and chronic peer stress was moderated by developmental factors. Results showed that older aged adolescents with SS/SL genotype, who experienced higher peer chronic stress over 3 years, were the most likely to be diagnosed with a depressive episode over time. Girls experiencing greater peer chronic stress were the most likely to develop depression. This study used repeated assessments of diagnostic interviewing in a moderately large sample of youth over 3 years to show that depression rates increase in middle to late adolescence, or postpubertally, and that the gender difference in depression emerges earlier in adolescence (age 12.5), or postpubertally. Additionally, genetically susceptible older adolescents who experience chronic peer stress were the most likely to become depressed over time.

Stress sensitivity interacts with depression history to predict depressive symptoms among youth: prospective changes following first depression onset.

Predictors of depressive symptoms may differ before and after the first onset of major depression due to stress sensitization. Dependent stressors, or those to which characteristics of individuals contribute, have been shown to predict depressive symptoms in youth. The current study sought to clarify how stressors' roles may differ before and after the first depressive episode. Adolescents (N = 382, aged 11 to 15 at baseline) were assessed at baseline and every 3 months over the course of 2 years with measures of stressors and depressive symptoms. Semi-structured interviews were conducted every 6 months to assess for clinically significant depressive episodes. Hierarchical linear modeling showed a significant interaction between history of depression and idiographic fluctuations in dependent stressors to predict prospective elevations of symptoms, such that dependent stressors were more predictive of depressive symptoms after onset of disorder. Independent stressors predicted symptoms, but the strength of the association did not vary by depression history. These results suggest a synthesis of dependent stress and stress sensitization processes that might maintain inter-episode depressive symptoms among youth with a history of clinical depression.

Parent relationship quality buffers against the effect of peer stressors on depressive symptoms from middle childhood to adolescence.

During the transition to adolescence, several developmental trends converge to increase the importance of peer relationships, the likelihood of peer-related stressors, and the experience of depressive symptoms. Simultaneously, there are significant changes in parent-child relationships. The current study sought to evaluate whether positive relationship quality with parents continued to serve a protective effect by buffering the relationship between stressful life events, especially peer stress, and increases in depressive symptoms throughout the transition to adolescence. Participants in a large (N = 692) 2-site accelerated longitudinal study were recruited in 3rd, 6th, and 9th grade and followed every 3 months for 1 year. At baseline, parents and youth reported on parent-child relationship quality, and every 3 months thereafter reported on their levels of stressors and depressive symptoms. Parent relationship quality moderated the relationship of person-level fluctuations in peer stressors, such that there was a stronger association between peer stressors and increases in depressive symptoms in youth with lower levels of positive parental relationship quality. This effect was specific to peer stressors. These results suggest that low levels of parent relationship quality leave youth particularly vulnerable to the depressogenic effects of peer stressors from childhood through adolescence.

Rumination and Excessive Reassurance Seeking: Investigation of the Vulnerability Model and Specificity to Depression.

Recent research investigating cognitive and interpersonal models of depression have conceptualized rumination and excessive reassurance seeking (ERS) as vulnerabilities for the etiology of depression. However, research testing the vulnerability hypothesis for these constructs among youth is lacking. Additionally, the specificity of rumination and excessive reassurance seeking to depression is unclear. Two studies investigated associations between these constructs to depression and anxiety. In Study 1, concurrent associations between these constructs and depressive and anxious arousal were examined among 194 minority, underserved youth. Study 2 examined concurrent and longitudinal associations between both constructs and depressive and general anxiety symptoms in a community sample of 402 youth. Results from both studies supported rumination as a specific vulnerability for depressive symptoms, whereas ERS appeared to be a concomitant of negative affect common to depressive and anxiety symptoms. Findings inform cognitive and interpersonal theories of depression by advancing knowledge of how rumination and ERS relate to aspects of internalizing problems among diverse populations of youth.

Developmental perspectives on vulnerability to nonsuicidal self-injury in youth.

Nonsuicidal self-injury (NSSI) is defined as intentionally causing bodily harm to oneself without the intent to kill oneself. Recently, there has been an increase in research aimed at understanding why individuals, especially youth and young adults, engage in NSSI. This chapter explores the emergence and maintenance of NSSI from a developmental perspective. Epidemiological research suggests that rates of NSSI increase dramatically from early adolescence to young adulthood. No study has investigated NSSI in youth younger than age 10. Current understanding of how emotion and cognitions as well as interpersonal processes play a role in the emergence and maintenance of NSSI is explored. Further, the role of biology (e.g., neurological underpinnings, genetic associations, HPA-axis functioning) on NSSI is explored. Throughout the chapter, particular limitations (e.g., sample selection, measurement issues) in the extant corpus of knowledge are highlighted. Finally, we consider future research directions that may inform developmentally sensitive understanding of the proximal and distal risk factors that may affect the emergence and maintenance of NSSI across the life span.