A pinboard by
Michelle Lamblin

PhD Student , Monash University


Exploring the impact of social networks on the developing adolescent brain

Adolescence is a period of significant physical, emotional and social development, and teenage friendships play a big role in that. Teenagers’ brains are still growing and developing at this time, as brain systems that process social information and emotions are still maturing. The interaction between the social environment and developing brain can have important implications for youth mental health.

For my PhD, I asked 250 high school students to tell me who their friends are, and how close they are to each friend. I use this information to create a map of the school "social network", including all the friendships and connections in the year level. A number of these students then complete an MRI brain scan, where I take scans of the structure, function and neural connectivity of their brains, and compare this to their position within their school social network. From here, I can analyse the patterns of brain activity between socially connected students to determine whether friends have more similar brains than non-friends. Once I have created a brain profile of each student and compared it to those of their friends, I may be able to tell if there is something about a teenager’s brain that makes it more or less likely that two individuals will become friends. Hopefully by better understanding what drives teenage friendships, we can provide health and educational support to promote social connectedness and better mental health outcomes for teenagers.


The spread of sleep loss influences drug use in adolescent social networks.

Abstract: Troubled sleep is a commonly cited consequence of adolescent drug use, but it has rarely been studied as a cause. Nor have there been any studies of the extent to which sleep behavior can spread in social networks from person to person to person. Here we map the social networks of 8,349 adolescents in order to study how sleep behavior spreads, how drug use behavior spreads, and how a friend's sleep behavior influences one's own drug use. We find clusters of poor sleep behavior and drug use that extend up to four degrees of separation (to one's friends' friends' friends' friends) in the social network. Prospective regression models show that being central in the network negatively influences future sleep outcomes, but not vice versa. Moreover, if a friend sleeps </=7 hours, it increases the likelihood a person sleeps < or =7 hours by 11%. If a friend uses marijuana, it increases the likelihood of marijuana use by 110%. Finally, the likelihood that an individual uses drugs increases by 19% when a friend sleeps < or =7 hours, and a mediation analysis shows that 20% of this effect results from the spread of sleep behavior from one person to another. This is the first study to suggest that the spread of one behavior in social networks influences the spread of another. The results indicate that interventions should focus on healthy sleep to prevent drug use and targeting specific individuals may improve outcomes across the entire social network.

Pub.: 25 Mar '10, Pinned: 31 Jul '17

Transitions in Friendship Attachment During Adolescence are Associated With Developmental Trajectories of Depression Through Adulthood.

Abstract: Forming secure friendship attachments during adolescence are important for mental health; few, however, have specifically examined the ways in which the transitions in attachment during adolescence may influence future mental health outcomes among African Americans.The present study examines how transitions in attachment in adolescence predicted changes in depression symptoms from late adolescents through adulthood in an African-American sample. We used growth curve modeling to examine the association between transitions in friendship attachment and changes in depression symptoms in adulthood.At age 16 years, 346 (64.0%) adolescents reported secure attachment with 195 (36.0%) reporting either avoidant or resistant attachment. At age 17 years, 340 (62.9%) reported secure attachment and 201 (37.2%) reported avoidant or resistant attachment. The largest percentage of participants (46.2%) reported stable-secure attachment across the two time points. Results of the growth model indicated that adolescents who reported a stable-secure attachment style had lower levels of depression symptoms during adulthood than those individuals who transitioned from secure-to-insecure, from insecure-to-secure, or were in the stable-insecure group. Interestingly enough, individuals in both the attachment transition groups had a faster declining rate of depression symptoms over time compared to the two stability groups.Data support existing research showing an association between transitions in attachment during adolescence and depression through adulthood. Furthermore, these study findings suggest there may be protective features associated with transitioning between attachment styles during adolescence on later depression, compared to African Americans who remain stable in their attachment style.

Pub.: 24 Feb '16, Pinned: 31 Jul '17

Adolescent friendships predict later resilient functioning across psychosocial domains in a healthy community cohort.

Abstract: Adolescence is a key time period for the emergence of psychosocial and mental health difficulties. To promote adolescent adaptive ('resilient') psychosocial functioning (PSF), appropriate conceptualisation and quantification of such functioning and its predictors is a crucial first step. Here, we quantify resilient functioning as the degree to which an individual functions better or worse than expected given their self-reported childhood family experiences, and relate this to adolescent family and friendship support.We used Principal Component and regression analyses to investigate the relationship between childhood family experiences and PSF (psychiatric symptomatology, personality traits and mental wellbeing) in healthy adolescents (the Neuroscience in Psychiatry Network; N = 2389; ages 14-24). Residuals from the relation between childhood family experiences and PSF reflect resilient functioning; the degree to which an individual is functioning better, or worse, than expected given their childhood family experiences. Next, we relate family and friendship support with resilient functioning both cross-sectionally and 1 year later.Friendship and family support were positive predictors of immediate resilient PSF, with friendship support being the strongest predictor. However, whereas friendship support was a significant positive predictor of later resilient functioning, family support had a negative relationship with later resilient PSF.We show that friendship support, but not family support, is an important positive predictor of both immediate and later resilient PSF in adolescence and early adulthood. Interventions that promote the skills needed to acquire and sustain adolescent friendships may be crucial in increasing adolescent resilient PSF.

Pub.: 12 Apr '17, Pinned: 31 Jul '17

Mental health and social networks in early adolescence: a dynamic study of objectively-measured social interaction behaviors.

Abstract: How are social interaction dynamics associated with mental health during early stages of adolescence? The goal of this study is to objectively measure social interactions and evaluate the roles that multiple aspects of the social environment--such as physical activity and food choice--may jointly play in shaping the structure of children's relationships and their mental health. The data in this study are drawn from a longitudinal network-behavior study conducted in 2012 at a private K-8 school in an urban setting in California. We recruited a highly complete network sample of sixth-graders (n = 40, 91% of grade, mean age = 12.3), and examined how two measures of distressed mental health (self-esteem and depressive symptoms) are positionally distributed in an early adolescent interaction network. We ascertained how distressed mental health shapes the structure of relationships over a three-month period, adjusting for relevant dimensions of the social environment. Cross-sectional analyses of interaction networks revealed that self-esteem and depressive symptoms are differentially stratified by gender. Specifically, girls with more depressive symptoms have interactions consistent with social inhibition, while boys' interactions suggest robustness to depressive symptoms. Girls higher in self-esteem tended towards greater sociability. Longitudinal network behavior models indicate that gender similarity and perceived popularity are influential in the formation of social ties. Greater school connectedness predicts the development of self-esteem, though social ties contribute to more self-esteem improvement among students who identify as European-American. Cross-sectional evidence shows associations between distressed mental health and students' network peers. However, there is no evidence that connected students' mental health status becomes more similar in their over time because of their network interactions. These findings suggest that mental health during early adolescence may be less subject to mechanisms of social influence than network research in even slightly older adolescents currently indicates.

Pub.: 07 May '14, Pinned: 31 Jul '17

Neural connections foster social connections: a diffusion-weighted imaging study of social networks.

Abstract: Although we know the transition from childhood to adulthood is marked by important social and neural development, little is known about how social network size might affect neurocognitive development or vice versa. Neuroimaging research has identified several brain regions, such as the amygdala, as key to this affiliative behavior. However, white matter connectivity among these regions, and its behavioral correlates, remain unclear. Here we tested two hypotheses: that an amygdalocentric structural white matter network governs social affiliative behavior and that this network changes during adolescence and young adulthood. We measured social network size behaviorally, and white matter microstructure using probabilistic diffusion tensor imaging in a sample of neurologically normal adolescents and young adults. Our results suggest amygdala white matter microstructure is key to understanding individual differences in social network size, with connectivity to other social brain regions such as the orbitofrontal cortex and anterior temporal lobe predicting much variation. In addition, participant age correlated with both network size and white matter variation in this network. These findings suggest the transition to adulthood may constitute a critical period for the optimization of structural brain networks underlying affiliative behavior.

Pub.: 13 Jan '16, Pinned: 31 Jul '17