Longitudinal changes in behavioral approach system sensitivity and brain structures involved in reward processing during adolescence.

Abstract

Adolescence is a period of radical normative changes and increased risk for substance use, mood disorders, and physical injury. Researchers have proposed that increases in reward sensitivity, i.e., sensitivity of the behavioral approach system (BAS), and/or increases in reactivity to all emotional stimuli (i.e., reward and threat sensitivities) lead to these phenomena. The present study is the first longitudinal investigation of changes in reward (i.e., BAS) sensitivity in 9 to 23-year-olds across a two-year follow-up. We found support for increased reward sensitivity from early to late adolescence and evidence for decline in the early twenties. This decline is combined with a decrease in left nucleus accumbens (Nacc) volume, a key structure for reward processing, from the late teens into the early twenties. Furthermore, we found longitudinal increases in sensitivity to reward to be predicted by individual differences in the Nacc and medial OFC volumes at baseline in this developmental sample. Similarly, increases in sensitivity to threat (i.e., BIS sensitivity) were qualified by sex, with only females experiencing this increase, and predicted by individual differences in lateral OFC volumes at baseline.

The Developmental Mismatch in Structural Brain Maturation during Adolescence

“…For the NAcc, the best fitting group model displayed a linear decrease in volume throughout the studied age range (8-25 years). This result is similar to that found in previous longitudinal studies of NAcc structural development [5,6], which also reported linear decreases in adolescence, although there have been contrasting results [7,8]. Taken together, the current report and previous studies suggest that, at a group level, the NAcc decreases in volume between adolescence and adulthood, whereas it is likely that the amygdala increases in late childhood and early adolescence before stabilizing in volume by mid-to-late adolescence, with significant interindividual variability in the development of both regions.…”

“…In a longitudinal study of 60 adolescents (120 scans) between the ages of 12 and 16 years, the amygdala showed little change in volume, and the NAcc showed different developmental patterns by hemisphere, increasing in volume in the left hemisphere and decreasing in volume in the right hemisphere [7]. One of the few studies that has directly assessed the relationship between structural brain changes in adolescence with behavior found nonlinear development in the NAcc and no developmental changes for the amygdala [8]. In a sample of 184 individuals (341 scans) aged 9-23 years, the left NAcc appeared to show an increase from early to late adolescence, and approximately an 8% decrease from late adolescence to early adulthood (late teens to early 20s), whereas the right NAcc and bilateral amygdala did not show any age-related changes [8].…”

“…One of the few studies that has directly assessed the relationship between structural brain changes in adolescence with behavior found nonlinear development in the NAcc and no developmental changes for the amygdala [8]. In a sample of 184 individuals (341 scans) aged 9-23 years, the left NAcc appeared to show an increase from early to late adolescence, and approximately an 8% decrease from late adolescence to early adulthood (late teens to early 20s), whereas the right NAcc and bilateral amygdala did not show any age-related changes [8]. Reported positive affective responses to rewards were highest in late adolescence, decreasing into young adulthood in a developmental pattern similar to that of the left NAcc volume, thereby providing the first evidence linking structural brain development to reward sensitivity in adolescence [8].…”

Correlatos estructurales de las alteraciones cognitivas en niños con TEA

“…Los aumentos en el volumen del hipocampo fueron mayores en el hemisferio derecho. El aumento de volumen en el hipocampo, el globo pálido y núcleo accumbens izquierdo y la disminución de volumen en el putamen, el núcleo caudado, el tálamo y el núcleo accumbens derecho son en general coherentes con otras publicaciones (Durston et al, 2001;Sowell et al, 2002;Urošević et al, 2012). Los resultados del estudio apoyan la idea de que en este período de la vida se producen asimetrías en el desarrollo cerebral de estructuras subcorticales.…”

“…El volumen cortical total siguió un ajuste cuadrático que empezó a disminuir alrededor de los 12 años de edad. Encontraron que el grosor cortical disminuyó linealmente con la edad en todas las regiones corticales excepto en los polos temporales superior y medio bilaterales, que no cambia significativamente con la edad.Estos resultados del grosor cortical generalizado son consistentes con estudios previos (Sowell et al, 2004;Paus, Keshavan & Giedd, 2008;Muftuler et al, 2011 (Durston et al, 2001;Sowell et al, 2002;Urošević et al, 2012). Los resultados del estudio apoyan la idea de que en este período de la vida se producen asimetrías en el desarrollo cerebral de estructuras subcorticales.…”