Cognitive and Experienced Flexibility in Patients With Anorexia Nervosa and Obsessive Compulsive Disorder.

Objective: Anorexia nervosa (AN) and obsessive-compulsive disorder (OCD) share a neuropsychological profile characterized by cognitive inflexibility as evident in set-shifting problems, and by strong detail focus. Clinically, both patient groups display a strong rigidity which may be explained by these neurocognitive difficulties. Cognitive inflexibility may hinder treatment uptake and help explain suboptimal treatment outcomes in both AN and OCD. This is the first study to compare clinical AN and OCD groups andto examine similarities and differences in cognitive flexibility. Specifically, this study aims to investigate neuropsychological outcomes and self-reported difficulties in both clinical groups and a control group, and explore associations between the different flexibility outcomes and illness. Method: Two hundred participants (61 AN, 72 OCD and 67 HC) performed neuropsychological tasks on set-shifting abilities (Trail Making Task, Stroop color-word interference, Intradimensional-Extradimensional shift task), detail focus (Group Embedded Figures Test) and self-reported set-shifting abilities and attention to detail (DFlex). Results: Similarities between patient groups were found in terms of reduced set-shifting ability on the Trail Making Task and detail focus. Moreover, both patient groups self-reported more set-shifting problems but a less strong detail focus than HC, which in turn were not related to neuropsychological task outcomes in either of the groups. In both patient groups longer illness duration was associated to longer reaction times in the switching tasks and for both groups symptom severity was associated to higher experienced inflexibility and attention to detail. Conclusion: Cognitive inflexibility processes are largely similar in patients with AN and OCD. Both patient groups report inflexibility, yet this is unrelated to neuropsychological outcomes. Illness duration seems to contribute to poorer set-shifting and higher illness severity is linked to more experienced inflexibility. Findings highlight the need for entangling different domains of cognitive flexibility and detail focus and examining self-report measures for a cohesive understanding of clinically relevant flexibility weaknesses in AN and OCD.