A dive into the deep, mysterious waters of chronic fatigue and cognition in adolescents: Investigating subjective experiences of cognitive difficulties and objective measures of cognitive functioning

Abstract

Objective: The focus of the current study was to examine cognitive functioning by objective and subjective measures in adolescents with chronic fatigue (CF) and chronic fatigue syndrome (CFS). The results were compared between adolescents who developed CF/CFS and those who did not develop CF/CFS following acute EBV infection and healthy controls. To the extent of our knowledge, no studies to date on adolescents with CF/CFS have examined both subjective and objective cognitive functioning six months post EBV infection. Methods: Cognitive functioning of 195 adolescents was assessed six months after identification of acute EBV infection against 70 healthy controls. The EBV patients were divided into two main groups at six months; EBV (CF+), those who developed CF/CFS, and EBV (CF-), those who did not develop CF/CFS. Those who met the symptom requirements for CFS were further distinguished from the total group of adolescents with CF/CFS. Objective measures were assessed with neuropsychological tests. For subjective and clinical measures, various self-report questionnaires were applied. The data used in this thesis is cross-sectional and based on data already collected as part of the CEBA project. The groups were compared applying one-way ANOVA and Student’s t-test. Results: The total EBV (CF+) was not adversely affected on objective cognitive measures compared to EBV (CF-) and healthy controls. When measuring cognitive flexibility, verbal learning and verbal memory, the CFS subgroups performed worse compared to the total EBV (CF+) group. EBV (CF+) reported significantly more cognitive problems compared to EBV (CF-) and healthy controls. The CFS subgroups reported more subjective cognitive difficulties compared to the total EBV (CF+) group. Conclusion: The total group of adolescents with CF/CFS was not adversely affected on objective measures compared to the non-fatigued and healthy controls. Our findings suggest that adolescents who were diagnosed with CFS were more severely affected on both subjective and objective measures of cognitive functioning, which may indicate that symptom severity in patients with CF/CFS contributes to reduced cognitive functioning and should be addressed in future research. [The Chronic Fatigue Following Acute EBV Infection in Adolescents (CEBA) project is a doctoral thesis and a prospective cohort study investigating fatigue development, conducted at the Department of Paediatrics, Akershus University hospital]