This is a biobehavioral, longitudinal investigation of the role of emotion in the development of psychopathology in adolescence. The focus is on (a) the role of negative emotions in the development of psychopathology, and (b) socialization experiences and biological processes that contribute to emotion dysregulation and disorder. The dysregulated experience and expression of emotion is implicated in both externalizing (antisocial patterns) and internalizing (anxiety, depressed mood) disorders. Adolescence is a critical juncture in the development of these disorders. The incidence of psychopathology increases during this time period, and clinical problems become more differentiated along gender lines. Adolescents with comorbid externalizing and internalizing problems ranging from normal to subclinical to clinical levels are studied. Youth range in age from 11 to 16 years and are seen at two time points, spaced two years apart. Equal numbers of males and females are studied in order to examine etiology of sex differences in symptoms, emotion regulation, and developmental changes in how disorders manifested. A multi-method, multi-respondent approach is used. Time 1 includes physiological and and neurohormonal functioning (ANS, HPA), behavioral observations of youth and family, experimental paradigms, structured psychatric interviews and questionnaires. Time 2 outcomes are based on interview and questionnaire methods. Data collection has been completed for both time points and all data files have been constructed. Current projects are described below. (1) One focus of study is on socialization influences. In one report, parenting practices that were unsupportive or that magnified the adolescents? emotions were associated with heightened rumination, a practice known to predict subsequent depressive episodes. Female relative to male adolescents were a particular risk for developing ruminative response styles that may lead to more depression. Another report found differences in how parents socialize emotions in their daughters and sons, as well as differences in how mothers and fathers respond to their adolescents? emotions. Fathers were more likely than mothers to adhere to sex-stereotyped methods of socialization, e.g. attempting to suppress emotion in sons. Parents were more likely to encourage expression of all negative emotions (e.g. fear, sadness, anger), in their daughters than sons. Parents of youth with emotional and behavioral problems were the most likely to be punitive and dismissive of their children?s emotions. (2) Another focus of the study emphasizes neurohormonal and other physiological (ANS activity) characteristics of youth who vary in risk for emotional and behavioral problems. One report indicates relations between subjective emotion and cardiovascular measures during mood induction procedures; also finding, however, that youth with more problems were particularly likely to show de-coupling of subjective and physiological arousal. This may point to a system of affect dysregulation that compromises adaptive functioning. A second report examines relations between stress, coping, and cortisol?s diurnal rhythm and declivity in response to social challenge comparing low and high-risk adolescents. The diurnal rhythm was theoretically informative for understanding high-risk girls and boys, regardless of risk, whereas declivity in low-risk girls primarily informed ideas about cortisol regulation in relation to stress and coping. Cortisol levels were related to suicidality in high-risk boys and high-risk girls only, and patterns differed according to sex of child. Three empirical manuscripts based on current findings are under editorial review. Ongoing longitudinal analyses examine the contributions of these environmental and biological factors to different developmental trajectories (i.e. increases, decreases, shifts, and lack of change in psychiatric symptoms annd psychological problems over time). Such analyses can help to illuminate the interaction of biological factors and socialization experiences that influence the form of expression of psychopathology in adolescent males and females. This is a final report.