Objective: The purpose of this study was to determine the prevalence of severe fatigue in adolescent boys and girls, to explore the role of lifestyle factors in fatigue, and to investigate whether severe fatigue in a healthy population is associated with depression, anxiety, and comorbid factors also observed in chronic fatigue syndrome patients.
Methods: In a sample of 1718 boys and 1749 girls, fatigue severity and duration were measured using a multidimensional questionnaire (Checklist Individual Strength). In addition, self-reports of depressive symptoms, anxiety, chronic fatigue syndrome-related symptoms, and lifestyle characteristics were assessed by means of questionnaires. Prevalence rates of severe fatigue and severe fatigue for > or =1 month, based on a clinical cutoff score of the Checklist Individual Strength, were determined for boys and girls separately, and gender-specific predictors of fatigue were identified by multiple regression analysis.
Results: The data showed high prevalence rates of severe fatigue in adolescents. Remarkable differences between boys and girls were observed: 20.5% of girls and 6.5% of the boys scored above the clinical cutoff score on the Checklist Individual Strength. Of these subjects 80.0% of the girls and 61.5% of the boys reported severe fatigue for > or =1 month. Of the examined lifestyle characteristics, only sleep characteristics and the participation in sports played a role in predicting fatigue in both genders. Moreover, in girls, fatigue was associated with higher age, an early menarche, medication use, and the absence of an additional job. Overall, girls scored higher on depression, anxiety, and chronic fatigue syndrome-related symptoms. However, the relation between fatigue and these comorbid symptoms did not differ between genders. In both girls and boys, the duration of fatigue was positively related to fatigue severity, severity of depression and anxiety, and the number of chronic fatigue syndrome-related symptoms.
Conclusions: Fatigue prevalence among adolescents is high, especially in girls. Adolescent girls seem to be more vulnerable to symptoms of fatigue and comorbidity than boys. Interestingly, despite a female predominance in complaints, the relation between fatigue and depression, anxiety, and chronic fatigue syndrome-related symptoms was not gender specific and emerged as a cluster. In both genders, fatigue duration was associated with the severity of fatigue and the level of psychological comorbidity and chronic fatigue syndrome-related symptoms, and we, therefore, hypothesize that enduring severe fatigue may form a risk factor for the development of chronic fatigue syndrome.