Early-life stress (ELS), a complex traumatic stress including abuse, neglect and bullying during childhood or adolescence, is closely related to the development of psychiatric disorders. Conduct of a prospective study on the effect of ELS in human subjects is difficult due to ethical issues and limitations, and animal model study can be a reasonable alternative. Articles regarding structural and functional changes in the animal brain associated with ELS have been reviewed in this study. An up-to-date literature search on the effect of ELS on animal brain was performed ; keywords included ELS, central nervous system (CNS), and animal study using PubMed. A total of 623 articles were found and important articles were reviewed. First, we summarized the neurobiological changes in CNS associated with ELS, and then the effects of ELS on emotional and cognitive function and behavioral characteristics were recapped. ELS can induce overreactivity of the hypothalamus-pituitary-adrenal axis and cortical-subcortical structural changes including prefrontal cortex, hippocampus, and amygdala. These changes may be associated with neuroendocrine, cognitive, and emotional dysfunctions and related behavioral changes. Although most animal model studies used a single mode of stress, ELS tends to be experienced with complex types in human-life. Design of a new animal model examining the effects of complex trauma during early-life is important. Studies on the association between complex trauma and brain development can provide important insights regarding the pathogenetic mechanism of complex psychiatric disorders such as personality disorder and treatment-resistant depression.
Adolescent ; Amygdala ; Animals* ; Brain ; Bullying ; Central Nervous System* ; Cognition ; Depression ; Ethics ; Hippocampus ; Humans ; Models, Animal* ; Personality Disorders ; Prefrontal Cortex ; Prospective Studies

OBJECTIVES: In South Korea (hereafter Korea), the number of adolescent offspring of immigrants has rapidly increased since the early 1990s, mainly due to international marriage. This research sought to examine the association between the experience of school violence and mental health outcomes, and the role of help-seeking behaviors in the association, among biethnic adolescents in Korea. METHODS: We analyzed cross-sectional data of 3627 biethnic adolescents in Korea from the 2012 National Survey of Multicultural Families. Based on the victim's help-seeking behavior, adolescents who experienced school violence were classified into three groups: 'seeking help' group; 'feeling nothing' group; 'not seeking help' group. Multivariate logistic regression was applied to examine the associations between the experience of school violence and depressive symptoms for males and females separately. RESULTS: In the gender-stratified analysis, school violence was associated with depressive symptoms in the 'not seeking help' (odds ratio [OR], 7.05; 95% confidence interval [CI], 3.76 to 13.23) and the 'seeking help' group (OR, 2.77; 95% CI, 1.73 to 4.44) among male adolescents after adjusting for potential confounders, including the nationality of the immigrant parent and Korean language fluency. Similar associations were observed in the female groups. However, in the 'feeling nothing' group, the association was only significant for males (OR, 8.34; 95% CI, 2.82 to 24.69), but not females (OR, 0.77; 95% CI, 0.18 to 3.28). CONCLUSIONS: This study suggests that experience of school violence is associated with depressive symptoms and that the role of victims' help-seeking behaviors in the association may differ by gender among biethnic adolescents in Korea.
Adolescent ; Bullying/*ethics ; Child ; Cross-Sectional Studies ; *Depression ; Emigrants and Immigrants ; Female ; *Help-Seeking Behavior ; Humans ; Interviews as Topic ; Logistic Models ; Male ; Minority Health/*ethics ; Odds Ratio ; Racism ; Republic of Korea ; Risk Factors ; Schools ; Sex Factors ; Surveys and Questionnaires ; Young Adult