2011

Medically unexplained somatic complaints (MUSC; e.g., headaches, abdominal pain) are common in youths and may lead to increased medical consumption, poorer academic attainment, and future somatic ill-health. Dysfunction of the autonomic nervous system as one of the major physiological stress systems has been suggested as an important mechanism in MUSC, although literature is still inconsistent. Currently, large-sized studies using a dimensional approach regarding MUSC in youths are lacking, as is research into patterns of physiological functioning that discriminate between MUSC and anxiety and depression symptoms. The aim of this study was to investigate the relationship of dimensionally measured MUSC with high frequency (HF) HRV and baroreflex sensitivity (BRS) in a large preadolescent population cohort, taking into account co-occurring internalizing symptoms. Our study suggests reduced autonomic flexibility (i.e., lower HF-HRV and lower BRS) in relation to MUSC, independent of co-occurring internalizing symptoms and other important confounders. We provide additional evidence to an earlier TRAILS study, which reported a negative association between cardiac measures (HRV, BRS) and somatic-depressive symptoms (e.g., lack of appetite, overtiredness, Bosch et al., 2009), both studies tapping into different aspects of MUSC. We recommend to take account of MUSC in anxiety and depression research in relation to cardiac autonomic functioning, as findings may differ according to the magnitude of co-occurring MUSC.

Purpose. Low intelligence is a risk factor for functional somatic symptoms (FSS) in adults, but it is unknown whether a similar association exists in adolescents. We hypothesized that low intelligence may lead to FSS and that this association is mediated by low school performance. In addition, we hypothesized that this mediation is particularly present in adolescents who perceive high parental expectations. Methods. This study was performed in a general population cohort from the TRacking Adolescents’ Individual Lives Survey, using data from the first wave (n = 2,230, mean age = 11.09 years, SD = 0.56, 50.8% girls), second wave (n = 2,149, mean age = 13.65 years, SD = 0.53, 51.0% girls), and third wave (n = 1,816, mean age = 16.25 years, SD = 0.72, 53.3% girls). Intelligence was measured using the Wechsler Intelligence Scale for Children-Revised, which resulted in an intelligence quotient (IQ) for each participant. FSS were measured by the Somatic Complaints Scale of the Youth Self-Report. School performance was assessed by teacher reports and perceived parental expectations by adolescent reports. Structural equation modelling was used to test our hypotheses. Results. We found a significant negative association between IQ and FSS in the whole group (0.24). This association was significant in the group perceiving high parental expectations (0.37), but not in the group perceiving low parental expectations. The association between IQ and FSS was not mediated by school performance. Conclusions. Low intelligence is associated with a higher predisposition for FSS in adolescents, especially in those adolescents perceiving high parental expectations.
 

Objective. To examine whether school absenteeism is a perpetuating factor of functional somatic symptoms and whether this holds true for bullied adolescents. Study design. This study is part of the longitudinal population-based study Tracking Adolescents’ Individual Lives Survey. Data from assessment wave 2 (n = 2149; 51.0% girls; mean age = 13.65, SD = 0.53) and assessment wave 3 (n = 1816; 53.3% girls; mean age = 16.25, SD = 0.72) were used. Peer victimization was assessed by peer nominations, school absenteeism by both parent and teacher reports, and functional somatic symptoms with the Youth Self-Report. Results. With structural equation modeling, school absenteeism at the second wave, adjusted for functional somatic symptoms at the second wave, was reavealed to predict functional somatic symptoms at the third wave in the entire cohort (b = 0.12; 95% CI, 0.02- 0.22), but not in the subgroup of bullied adolescents (b = -0.13; 95% CI, -0.62-0.26). However, the difference between bullied and unbullied adolescents did not reach significance. Conclusion. This study provides evidence that school absenteeism is a perpetuating factor of functional somatic symptoms in adolescents. A clinical intervention study is necessary to examine whether preventing school absenteeism truly helps to reduce functional somatic symptoms in adolescents.

Background. Functional somatic symptoms (FSS), symptoms not explained by conventional medical conditions, are more prevalent in girls than in boys and this difference tends to increase during adolescence. This might be explained, at least in part, by pubertal development. We hypothesized that progressing through puberty is a risk factor for the development of most FSS, and that this is especially true for girls. Method. We used two longitudinal population based studies to examine our hypotheses, the Longitudinal Study of Pain in Adolescents in Seattle (N = 1,996, 49.7% girls) and the Dutch Tracking Adolescents’ Individual Lives Survey (N = 2,230, 51.0% girls). Two assessment waves of each study were used. American adolescents were younger than Dutch adolescents at the first (11.6 versus 13.6) and second (14.5 versus 16.2) assessment wave, but were in about the same pubertal development stage. FSS were measured by pain questions, the Symptom Check List, and the Youth Self-Report. The Pubertal Development Scale was used to assess pubertal development in both cohorts.
Results. Ordinal logistic regression analyses revealed that American and Dutch adolescents who were at a later pubertal status at baseline were more likely (odds ratios ranging from 1.24 to 1.61) to report back pain, overtiredness, and dizziness, but not stomach pain and headache two to three years later. Although these relations were not equally strong for boys and girls, no significant gender differences were found. Conclusion. Pubertal status predicted the frequency of some, but not all, FSS at follow-up.