Longitudinal study in adolescent anorexia nervosa: evaluation of cortico-striatal and default mode network resting-state brain circuits.

Anorexia nervosa (AN) typically emerges in adolescence. The cortico-striatal system (CSTS) and the default mode network (DMN) are brain circuits with a crucial development during this period. These circuits underlie cognitive functions that are impaired in AN, such as cognitive flexibility and inhibition, among others. Little is known about their involvement in adolescent AN and how weight and symptom improvement might modulate potential alterations in these circuits. Forty-seven adolescent females (30 AN, 17 healthy control) were clinically/neuropsychologically evaluated and scanned during a 3T-MRI resting-state session on two occasions, before and after a 6-month multidisciplinary treatment of the AN patients. Baseline and baseline-to-follow-up between-group differences in CSTS and DMN resting-state connectivity were evaluated, as well as their association with clinical/neuropsychological variables. Increased connectivity between the left dorsal putamen and the left precuneus was found in AN at baseline. At follow-up, body mass index and clinical symptoms had improved in the AN group. An interaction effect was found in the connectivity between the right dorsal caudate to right mid-anterior insular cortex, with lower baseline AN connectivity that improved at follow-up; this improvement was weakly associated with changes in neuropsychological (Stroop test) performance. These results support the presence of CSTS connectivity alterations in adolescents with AN, which improve with weight and symptom improvement. In addition, at the level of caudate-insula connectivity, they might be associated with inhibitory processing performance. Alterations in CSTS pathways might be involved in AN from the early stages of the disorder.