Neural Mechanisms of Executive Function Tasks in Obsessive-Compulsive Disorder and Anorexia Nervosa: A Comparative Systematic Review

Executive functions are set of cognitive tools that helps in navigating through a complex and unpredictable world. Prominent research has extensively evaluated the neural basis of executive functions in psychiatric disorders. Particularly, inferences on whether obsessive-compulsive disorder and anorexia nervosa present with similar brain activity whilst performing an executive function task were raised. This is due to the high comorbidity and shared symptomatology between the two disorders. Therefore, a systematic review was conducted to synthesize research that applied executive function tasks during functional magnetic resonance imaging in obsessive-compulsive disorder and anorexia nervosa. Following the PRISMA guidelines, 43 studies comparing the executive performance of patients of each disorder and healthy participants were chosen. This review revealed that although both disorders may activate similar brain areas, they may be engaging in diverse neural pathways for each executive function task. Conclusively, common notions on increased self-referential processing and discrepancy between internal and external models were given by most of the included studies. The evidence for comparing neural activation in both disorders was conflicting and incongruous. More research using consistent experimental paradigms and assessing both disorders concurrently is required.