Abstract
BACKGROUND: This study investigated the moderating role of household disposable income and family type on the association between precarious employment (PE) and diagnosed mental disorders. METHODS: This longitudinal study used register data from the Swedish Work, Illness, and Labour-market Participation (SWIP) cohort. The study population included all individuals aged 27–65 who were employed in 2016 (n = 2,509,229). Precarious employment was measured using the Swedish Register-based Operationalization of Precarious Employment (SWE-ROPE 2.0), which captures employment insecurity, income inadequacy, and lack of rights and protection. Diagnosed mental disorders during 2017–2019 were identified through national inpatient, outpatient, and prescription registers. Household disposable income and family type (2016) were examined as moderators. Cox regression models estimated the effect of precarious employment on diagnosed mental disorders, with moderation assessed using two-way interaction terms. RESULTS: The risk of diagnosed mental disorders was higher among those in PE (HR 1.21, 95% CI 1.18–1.23) compared with those in standard employment, across household income levels and family types. High household income was generally protective, but the interaction between PE and high income indicated that this protective effect was reduced for individuals in PE, both among men (interaction HR 1.22, 95% CI 1.04–1.43) and women (interaction HR 1.25, 95% CI 1.13–1.38). Among women, family types other than “couple without children” amplified the effects of PE on diagnosed mental disorders. The interaction for single mothers (HR 1.27, 95% CI 1.14–1.42) showed that the combined effect of PE and single motherhood exceeded the sum of their separate effects. CONCLUSION: Higher household income does not fully buffer the negative impact of PE on diagnosed mental disorders, and the negative impact of PE appears stronger for women, especially mothers. The findings are most generalisable to contexts with similar welfare regimes and gender norms. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-026-26259-x.