Abstract
Set-shifting difficulties have been suggested to underlie rigid and inflexible thinking in patients with anorexia nervosa (AN). Studies reported set-shifting deficiencies in adults with AN and also in their unaffected family members, suggesting that set-shifting deficits are heritable in AN. Surprisingly, studies failed to show set-shifting difficulties in adolescents with AN. If set-shifting difficulties are heritable, it is not clear why they are absent in adolescents with AN. The current study aimed to elucidate this discrepancy by assessing several components of set-shifting in adolescents with weight-restored AN (WR-AN) and their unaffected parents and siblings. Twenty-one families that include an adolescent who was diagnosed with AN prior to weight restoration (N = 19), an unaffected parent (N = 18), and an unaffected sibling (N = 20) were recruited. Additionally, 28 healthy control families were recruited and included an age-matched adolescent (N = 27), a parent (N = 26), and a sibling (N = 17). Visual-motor set-shifting, verbal set-shifting, and set-shifting clean of inhibition were assessed using the Delis-Kaplan Executive Function System. The results revealed intact set-shifting in parents and siblings of adolescents with WR-AN. Surprisingly, the results revealed superior visual-motor and verbal set-shifting in adolescents with WR-AN compared to age-matched controls. However, when controlling for inhibition abilities, poorer set-shifting was revealed in adolescents with WR-AN. The results suggest that superior inhibition abilities in adolescents with WR-AN may compensate for their set-shifting deficiencies. The study emphasizes the importance of controlling for inhibition abilities when assessing neurocognitive functioning in adolescents with AN. Furthermore, the study does not support the notion that set-shifting deficits are heritable in adolescent AN.