Multiple bodily symptoms predict poor health status, high healthcare use, and onset of functional somatic syndromes. This study aimed to identify the predictors of somatic symptoms with special reference to mental disorders.
The prospective, population-based Lifelines cohort study included 80,888 adults who were followed up for a mean of 2.4 years. At baseline sociodemographic status, self-reported medical disorders, functional somatic syndromes, stress, neuroticism, mental disorders (assessed with Mini-International Neuropsychiatric Interview), health perception, and analgesic use were assessed. These variables were tested as predictors of number of somatic symptoms at follow-up using linear regression analysis, which adjusted for baseline somatic symptoms (n = 65,904). Logistic regression was used to identify the predictors of a persistently high number of somatic symptoms.
The strongest predictors of somatic symptoms at follow-up were life events and difficulties score, and number of general medical illnesses/functional somatic syndromes. Neuroticism and mental disorders were also independent predictors in all analyses. Generalized anxiety, major depressive, and panic disorders were all independent predictors when entered individually into the regression analysis. A persistently high number of somatic symptoms were predicted most strongly by functional somatic syndromes, negative health perception, and paracetamol use.
Number of somatic symptoms should be regarded as a multifactorial measure with many predictors. Mental disorders form one predictor, but there are other stronger ones, including stress and general medical disorders. The bidirectional relationship between functional somatic syndromes and multiple somatic symptoms is compatible with the notion that perception of bodily symptoms is a key component of both.