Young women's somatic symptoms are more strongly predicted by psychosocial rather than physiological factors: longitudinal findings in a population-representative Australian sample.

OBJECTIVE: Somatic symptoms - persistent medically unexplained physical complaints - present a challenge for the healthcare system, partly because patients often resist psychological explanations and treatments. To inform patient-practitioner interactions, we provide country-specific population-representative longitudinal data on the relative contributions of physiological and psychosocial factors - individually, as specific targets for treatment, and as 'physiological' and 'psychosocial' variable clusters representing broad targets for treatment.

METHODS AND MEASURES: 8,261 women aged 22-27 from the Australian Longitudinal Study on Women's Health reported on eight physiological predictors and nine psychosocial predictors in 2017. In linear regressions both with and without missing data imputation, we assessed the relative contributions of predictors to an average score across 11 somatic symptoms reported in 2019. Supplementary analyses accounted for baseline somatic symptoms.

RESULTS: In the main analysis (with imputation, and without baseline symptoms), physiological predictors comprised two of the five strongest predictors but accounted for less variance than psychosocial predictors (11.6 vs. 29.6%). The two sets of predictors were correlated, as the total explained variance was 33.2%. Low income and stress were strong predictors across all analyses.

CONCLUSION: Practitioners could discuss the likely interplay of psychosocial and physiological processes and advise on affordable treatment options.