Examining accumulation and adaptation in psychosocial and material exposures and self-rated health: A fixed-effects approach within income groups using German panel data

Aims: This study investigates how continuous exposure to psychosocial and material factors influences self-rated health (SRH) trajectories in different income groups, uniquely contrasting two mechanisms from a life course perspective: accumulation, where disadvantages intensify with longer exposure, and adaptation, where individuals adjust to adverse conditions. Methods: Based on the German Socio-Economic Panel (1994–2017), we analyzed data from 31,961 women and 29,149 men (18–75 years; ⩾2 observations). Psychosocial and material factors (e.g. financial/occupational worries, housing/income dissatisfaction) were measured dichotomously and as continuous exposition. Income- and sex-stratified fixed-effects regressions examined within-individual associations between exposure duration and SRH, adjusting for social environment, occupational position, and life stages. Additional specifications included continuous age and time fixed-effects. Results: Longer continuous exposure to disadvantageous factors was associated with declining SRH, particularly for financial worries, housing status, and income dissatisfaction, consistent with the accumulation thesis. For example, after five years of financial worries, low-income men rated their SRH ~0.2 points lower on a five-point scale compared with shorter or no continuous exposure. Adjustment for continuous age and time fixed-effects mitigated some duration effects, especially in lower income groups, indicating partly overlap of the observed patterns with age- or time-related health dynamics. Patterns indicative of adaptation were modest, with little attenuation across continuous exposure for most factors. Conclusions: Results mainly support the accumulation thesis, while evidence for adaptation was limited. Future research should further examine income-specific trajectories, concurrent exposures, and age-related health dynamics, thereby reinforcing the importance of longitudinal life-course research on psychosocial and material factors.