Poverty linked to externalizing problems in early adolescence

Childhood poverty was associated with increases in externalizing problems, but not internalizing, over time in early adolescence, researchers reported in JAMA Network Open.

Childhood poverty has been linked to increased internalizing problems, such as depression and anxiety, and externalizing problems, such as aggression and hyperactivity, during adolescence, a period of peak onset for psychiatric problems, Hannah H. Kim, MS, of the department of social and behavioral sciences at Harvard T. H. Chan School of Public Health, and colleagues wrote.

Kim and colleagues sought to determine whether structural differences in cortical regions mediate the association between poverty and change in psychiatric symptoms in early adolescence.

The authors conducted a longitudinal cohort study that used baseline and follow-up data from the Adolescent Brain Cognitive Development Study. Children in the U.S. aged 9 to 10 years were enrolled from Sept. 1, 2016, through Oct. 15, 2018.

The authors obtained children’s cortical surface area, thickness and volume, which were used as mediators in the study. Internalizing and externalizing problems were measured by maternal report using the Child Behavior Checklist.

Of the 7,569 children (mean age, 9.91 years; 52.5% male) included in the analysis, 1,042 children (13.8%) lived below the poverty threshold.

Poverty was associated with increased externalizing symptoms score at 1-year follow-up (1.57; 95% CI, 1.14-1.99), as well as after adjusting for baseline externalizing symptoms (0.35; 95% CI, 0.06-0.64).

In addition, the longitudinal associations of poverty with increases in externalizing problems over time were mediated by reductions in surface area in multiple cortical regions that support executive function, decision-making, visual processing, auditory processing, as well as emotion and language processing, the authors wrote.

“These findings highlight potential neurobiological mechanisms underlying the link between poverty and the emergence of externalizing problems during early adolescence,” Kim and colleagues wrote.