Examination of poverty trajectories and brain volume as predictors of adolescent depression.

Adolescence is a sensitive period during which socioeconomic conditions can shape brain development and mental health. To further clarify such pathways, the present study examined how trajectories of different poverty indices across adolescence relate to brain structure and depressive symptomatology. In a sample of 206 Mexican-origin youth, latent growth curve modeling was used to assess parent-reported income-to-needs and economic hardship measured from ages 10 to 16 as predictors of self-reported depressive symptomatology at age 18. Youths also reported on perceived economic hardship at 14 and 16 years. Amygdala, hippocampus, anterior cingulate cortex, and ventromedial prefrontal cortex volumes assessed using structural magnetic resonance imaging at age 17 were examined as mediators within the models. Lower average income-to-needs across adolescence was associated with larger amygdala and hippocampal volumes, whereas youth-reported economic hardship predicted smaller anterior cingulate cortex volumes. Youth-reported economic hardship, but neither parent-reported economic hardship nor brain volumes, significantly predicted depression symptoms. Parent-reported economic hardship across adolescence was unrelated to both brain volume and depression symptoms. Results highlight that objective poverty and adolescents' own perceptions of hardship may each relate to neurodevelopment, and that youth-reported hardship may be more proximally linked to depressive symptomatology in late adolescence than parent-reported hardship or brain volume.