T he study by Lamers et al. in this issue (1) is important in several respects. Fatigue in adolescents was investigated in a large representative sample from the general population by structured interviews. The study demonstrated that persistent fatigue without anxiety or depression occurred in 1.4% of the adolescents. This prevalence rate is surprisingly high, and in about 60% of this group the fatigue was associated with substantial disability. Despite these disabilities, the adolescents with persistent fatigue without anxiety or depression generally did not seek help from the health care system. This reflects perhaps the assumption of both adolescents and health care professionals that fatigue is a transient state that will resolve spontaneously. But is that true? Or should more attention be paid to this debilitating symptom? Fatigue indeed occurs frequently in adolescents. It is not unusual that youngsters experiment with extreme behavior, thereby exhausting themselves. Usually the fatigue resolves when the adolescent changes his or her behavior. Fatigue becomes a problem if it persists and leads to disability, such as school absence, or if the adolescent feels continuously unable to be physically active (e.g., participate in sports) and socially involved (e.g., take part in festivities, go out). Then fatigue threatens the adolescent’s social, emotional, and intellectual development. In those instances, fatigue deserves attention from the health care system.