Daily Links Between Helping Behaviors and Emotional Well-Being During Late Adolescence.

We investigated daily associations between helping behaviors and emotional well-being during late adolescence, examining whether these links depend on the recipient of help (i.e., friend vs. roommate), type of help (i.e., instrumental vs. emotional), and individual differences in the helper (i.e., gender and empathy). First-year college students (N = 411, 63.5% women, Mage  = 18.62 years) completed diary checklists for eight days, reporting whether they provided instrumental and emotional support to a friend or roommate, and positive and negative emotions. On days that adolescents provided instrumental assistance to friends they felt more positive affect, but men also felt more negative affect. Providing instrumental and emotional support to roommates and providing emotional support to friends did not predict daily emotions.

Racial/ethnic disparities in cortisol diurnal patterns and affect in adolescence.

Racial/ethnic minorities are more vulnerable to mental and physical health problems, but we know little about the psychobiological underpinnings of these disparities. In this study, we examined racial/ethnic differences in cortisol diurnal patterns and affect as initial steps toward elucidating long-term health disparities. A racially/ethnically diverse (39.5% White, 60.5% minority) sample of 370 adolescents (57.3% female) between the ages of 11.9 and 18 years (M = 14.65 years, SD = 1.39) participated in this study. These adolescents provided 16 cortisol samples (4 samples per day across 4 days), allowing the computation of diurnal cortisol slopes, the cortisol awakening response, and diurnal cortisol output (area under the curve), as well as daily diary ratings of high-arousal and low-arousal positive and negative affect. Consistent with prior research, we found that racial/ethnic minorities (particularly African American and Latino youth) exhibited flatter diurnal cortisol slopes compared to White youth, F (1, 344.7) = 5.26, p = .02, effect size g = 0.25. Furthermore, African American and Asian American youth reported lower levels of positive affect (both high arousal and low arousal) compared to White youth. Racial/ethnic differences in affect did not explain differences in cortisol patterns, suggesting a need to refine our models of relations between affect and hypothalamic-pituitary-adrenocortical activity. We conclude by proposing that a deeper understanding of cultural development may help elucidate the complex associations between affect and hypothalamic-pituitary-adrenocortical functioning and how they explain racial/ethnic differences in both affect and stress biology.

Three-month cumulative exposure to testosterone and cortisol predicts distinct effects on response inhibition and risky decision-making in adolescents.

Prior studies have established that cortisol and testosterone play a role in impulsive behavior, but little is known about how cumulative exposure to these hormones over a recent period influences cognitive processes that help to regulate impulsive behavior. We addressed this gap in the present study by examining how hair concentrations of testosterone and cortisol related to response inhibition and risky decision-making in adolescents. Adolescents provided 3 cm of hair cut as close as possible to the scalp from a posterior vertex position-indexing three months of hair growth-and completed two behavioral tasks, one that measures response inhibition and the second that measures risky decision-making. We found that greater three-month cumulative exposure to testosterone predicted better response inhibition but was unassociated with risky decision-making, whereas greater three-month cumulative exposure to cortisol predicted less risky decision-making but was unassociated with response inhibition. These results suggest that testosterone and cortisol may be associated with unique cognitive processes underpinning impulsive behavior, providing further evidence for their roles in contributing to complex impulsive behaviors in adolescence.

Behavioral and Neural Dysregulation to Social Rewards and Links to Internalizing Symptoms in Adolescents.

Adolescence is a time of unique sensitivity to socially salient stimuli such as social rewards. This period overlaps with the onset of psychopathology such as internalizing and externalizing symptoms. In the current studies, we examined behavioral and neural patterns of dysregulation to social rewards and threats, and links to internalizing and externalizing symptoms in youths. In study 1, we used a social Go/NoGo cognitive control task using peer faces to test for age-related behavioral differences in inhibitory failures in adolescents (N = 53, Mage = 13.37 years), and adults (N = 51, Mage = 43.71 years). In study 2, an independent adolescent sample (N = 51, Mage = 13.98 years) completed a similar social Go/NoGo cognitive control task during fMRI. Results show that adolescents had greater inhibitory failures - as measured by false alarm rate - to both social reward and threat cues than adults, and more so to social reward than threat cues. Greater inhibitory failures to social reward than threat cues were associated with greater internalizing symptoms, but were not significantly related to externalizing symptoms. At the neural level, greater inhibitory failures to social reward than threat cues as well as greater internalizing symptoms were both associated with heightened amygdala-ventral striatum connectivity. Our findings indicate that subcortico-subcortical connectivity, which is deemed to occur chronologically earlier and thus necessary for subcortico-cortical circuits, may serve as an early biomarker for emotion dysregulation and a risk factor for internalizing symptoms.

Differential effects of parent and peer presence on neural correlates of risk taking in adolescence.

Adolescence is a developmental period associated with increased health-risk behaviors and unique sensitivity to the input from the social context, paralleled by major changes in the developing brain. Peer presence increases adolescent risk taking, associated with greater reward-related activity, while parental presence decreases risk taking, associated with decreased reward-related activity and increased cognitive control. Yet the effects specific to peers and parents are still unknown. The current functional magnetic resonance imaging (fMRI) study compared within-person peer and parent influences on risky decision-making during adolescence (ages 12-15 years; N = 56). Participants completed the Yellow Light Game (YLG), a computerized driving task, during which they could make safe or risky decisions, in the presence of a peer and their parent. Behavioral findings revealed no effects of social context on risk taking. At the neural level, a collection of affective, social and cognitive regions [ventral striatum (VS), temporo-parietal junction (TPJ), and dorsolateral prefrontal cortex (dlPFC)] was more active during decision-making with peers than parents. Additionally, functional connectivity analyses showed greater coupling between affective, social and cognitive control regions (VS-insula, VS-TPJ) during decision-making with parents than peers. These findings highlight the complex nature of social influence processes in peer and parent contexts, and contribute to our understanding of the opportunities and vulnerabilities associated with adolescent social sensitivity.

Neural correlates of sibling closeness and association with externalizing behavior in adolescence.

Sibling relationships have been linked to adolescent externalizing behaviors, but the neurobiological factors that underlie this association have not been identified. This study investigated sibling closeness and birth order as a predictor of adolescent externalizing behavior via differences in neural processes during safe decision-making. A total of 77 adolescents (range = 12-15 years, Mage = 13.45 years, 40 females) completed a computerized driving task during a functional MRI scan. Results showed that adolescents' perceptions of sibling closeness were associated with greater neural activation in the anterior insula, ventral striatum and left ventrolateral prefrontal cortex when making safe decisions, suggesting that the quality of sibling relationships modulates adolescent neurocognition even without being present. Furthermore, moderated mediation analyses revealed that higher sibling closeness was associated with lower externalizing behavior via left anterior insula activation during safe decision-making, but only for adolescents without older siblings (i.e. eldest children) compared to adolescents who had multiple older siblings. Importantly, these findings persisted above and beyond parental and peer closeness and sibling characteristics (i.e. sex, relatedness, birth order), highlighting the significant influence of sibling relationships on adolescent externalizing behavior through the brain.