This paper investigates how childhood socio-economic position influences the risk for midlife depressive and anxiety disorders at 45 years of age, assessed by the Clinical Interview Schedule in 9377 participants of the 1958 British Birth Cohort. Socio-economic position was measured by Registrar General Social Class in childhood and adulthood. The association of paternal manual socio-economic position with any diagnosis at 45 years of age was accounted for after adjustment for adult socio-economic position. Manual socio-economic position in women at 42 years of age was associated with midlife depressive disorder and any diagnosis; these associations were diminished by adjustment for childhood psychological disorders. Effects of childhood socio-economic position on adult depressive disorders may be mediated through adult socio-economic position.