Hippocampal Volume as an Amplifier of the Effect of Social Context on Adolescent Depression

Abstract

Recent models have focused on how brain-based individual differences in social sensitivity shape affective development in adolescence, when rates of depression escalate. Given the importance of the hippocampus in binding contextual and affective elements of experience, as well as its putative role in depression, we examined hippocampal volume as a moderator of the effects of social context on depressive symptoms in a sample of 209 Mexican-origin adolescents. Adolescents with larger versus smaller hippocampal volumes showed heightened sensitivity in their depressive symptoms to a protective factor inside the home (sense of family connectedness) and a risk factor outside of it (community crime exposure). These interactive effects uniquely predicted depressive symptoms and were greater for the left side, suggesting two independent social-contextual contributions to depression that were moderated by left hippocampal volume. Results elucidate complex brain-environment interplay in adolescent depression, offering clues about for whom and how social context plays a role.

An initial investigation of neonatal neuroanatomy, caregiving, and levels of disorganized behavior

“…In their longitudinal study of adolescents from, on average, 12 to 14 y of age, Whittle et al (55) found laboratory-assessed maternal aggression predictive of depressive symptoms, specifically among girls with comparatively large bilateral hippocampi. In addition, in their study of older adolescents, Schriber et al (41) observed depression both negatively related to family connectedness and positively related to community crime, specifically among adolescents with larger left hippocampi. Similar to our current findings, Schriber et al (41) did not observe a moderating influence of right hippocampal volume.…”

“…In addition, in their study of older adolescents, Schriber et al (41) observed depression both negatively related to family connectedness and positively related to community crime, specifically among adolescents with larger left hippocampi. Similar to our current findings, Schriber et al (41) did not observe a moderating influence of right hippocampal volume.…”

“…perhaps especially the left hippocampus (32,41), interacts with the environment to predict behavior and biology relevant to distress management. To better evaluate this possibility, future studies should include assessments of hippocampal volume both at the neonatal stage and near to the time disorganization is assessed.…”

“…Thus, by influencing associative memory, the left hippocampus may arbitrate the degree to which new information is integrated into schemas to influence subsequent thoughts and behavior. With this in mind, it is not surprising that the left hippocampus has also been proposed as a biomarker for differential susceptibility to negative (and positive) environmental input (41).…”

Direct replication of task‐dependent neural activation patterns during sadness introspection in two independent adolescent samples

“…Initially, participants were recruited when they were in fifth grade, drawn at random in two cohorts from school rosters during the 2006–2007 and 2007–2008 school years. About 6 years later, 229 participants (119 males and 110 females) were recruited into a substudy designed to examine neurobiological mechanisms in the etiology of depression (Schriber et al, ; Schriber et al, ; Weissman, Gelardi, et al, ; Weissman, Guyer, Ferrer, Robins, & Hastings, ). Youth with elevated depressive symptoms were oversampled from the CFP parent sample, using counts of adolescents' self‐reported symptoms in ninth grade (Age 14) on the Diagnostic Interview Schedule for Children‐IV (Shaffer, Fisher, Lucas, Dulcan, & Schwab‐Stone, ) and indicators of elevated severity from the Anhedonic Depression and General Distress subscales of the Mood and Anxiety Symptom Questionnaire (Watson & Clark, ).…”