Anxiety and depression are risk factors rather than consequences of functional somatic symptoms in a general population of adolescents: the TRAILS study.
BACKGROUND
It is well known that functional somatic symptoms (FSS) are associated with anxiety and depression. However, evidence is lacking about how they are related to FSS. The aim of this study was to clarify these relationships and examine whether anxiety and depression are distinctly related to FSS. We hypothesized that anxiety contributes to the development of FSS and that depression is a consequence of FSS.


METHODS
FSS, anxiety, and depression were measured in adolescents (N = 2230, 51% women) by subscales of the Youth Self-Report during three assessment waves (adolescents successively aged: 10-12, 12-14, and 14-17) and by corresponding subscales of the Child Behavior Checklist. Using structural equation models, we combined trait and state models of FSS with those of anxiety and depression, respectively. We identified which relationships (contemporaneous and two-year lagged) significantly connected the states of FSS with the states of anxiety and depression.


RESULTS
Trait variables were all highly interrelated (r = .54-.63). Contrary to our hypothesis, both state anxiety (beta = .35) and state depression (beta = .45) had a strong contemporaneous effect on state FSS. In turn, state FSS had a weak two-year lagged effect on state anxiety (beta = .11) and an even weaker effect on state depression (beta = .06).


CONCLUSIONS
While the effect of anxiety and depression on FSS is strong and immediate, FSS exert a weaker and delayed influence on anxiety and depression. Further research should be done to detect the exact ways in which anxiety and depression lead to FSS, and FSS lead to anxiety and depression.
Interdisciplinary Center for Psychiatric Epidemiology and Graduate Schools for Behavioral and Cognitive Neurosciences and for Health Research, University Medical Center Groningen, University of Groningen, 9700 RB, Groningen, The Netherlands. k.a.m.janssens@med.umcg.nl
Karin A M
KA
Janssens
Judith G M
JG
Rosmalen
Johan
J
Ormel
Floor V A
FV
van Oort
Albertine J
AJ
Oldehinkel
D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology*; D001007:Anxiety / Q000150:complications* / Q000523:psychology; D002648:Child; D003863:Depression / Q000150:complications* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D009426:Netherlands; D011446:Prospective Studies; D012307:Risk Factors; D013001:Somatoform Disorders / Q000175:diagnosis / Q000209:etiology* / Q000523:psychology*