Both mental disorders and personality characteristics are associated with impaired work functioning, but these determinants have not yet been studied together. The aim of this paper is to examine the impairing effects that mental disorders and personality characteristics (i.e. neuroticism, locus of control and self-esteem) have on work functioning.

Data for a representative sample of 3570 working people were derived from the first two waves of the Netherlands Mental Health Survey and Incidence Study (NEMESIS), a prospective cohort study in the Dutch adult population.

Higher neuroticism, more external locus of control and lower self-esteem were each significantly associated with subsequent impairment in work functioning, independently of any effects from mental disorders. Associations between mental disorders and subsequent work impairment disappeared once personality traits were taken into account. Personality traits did not moderate the relationships between mental disorders and work functioning.

Working people with vulnerable personalities have a greater risk of impaired work functioning, independent of the risk from any mental disorder they may have.