Risks for Developing Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in College Students Following Infectious Mononucleosis: A Prospective Cohort Study

BACKGROUND: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) involves severe fatigue, unrefreshing sleep, and cognitive impairment, leading to functional difficulties; prior studies have not evaluated risk factors with behavioral and immune data collected before developing ME/CFS. Up to 5% of university students develop infectious mononucleosis (IM) annually, and 9-12% meet criteria for ME/CFS 6 months later. We sought to determine predictors of ME/CFS. METHODS: We enrolled college students at the start of the school year (time 1), identified those who developed IM (time 2), and followed them for 6 months (time 3), identifying 3 groups: those who developed ME/CFS, severe ME/CFS (meeting >1 set of criteria), and who were asymptomatic. We conducted 8 behavioral and psychological surveys and analyzed cytokines at 3 time points. RESULTS: 238 of the 4501 students (5.3%) developed IM; 6 months later, 55 of the 238 (23%) met criteria for ME/CFS and 157 (66%) were asymptomatic. 67 of the 157 asymptomatic students served as controls. Students with severe ME/CFS were compared with students who were asymptomatic at 3 time points. The former group was not different from the latter group at time 1 (prior to developing IM) in stress, coping, anxiety, or depression but were different in several behavioral measures and had significantly lower levels of IL-6 and IL-13. At time 2 (when they developed IM), the 2 ME/CFS groups tended to have more autonomic complaints and behavioral symptoms while the severe-ME/CFS group had higher levels of IL-12 and lower levels of IL-13 than the recovered group. CONCLUSIONS: At baseline, those who developed ME/CFS had more physical symptoms and immune irregularities, but not more psychological symptoms, than those who recovered.