Psychological Medicine

Original Articles

The role of internalizing and externalizing liability factors in accounting for gender differences in the prevalence of common psychopathological syndromes

Mark D. Kramera1 c1, Robert F. Kruegera1 c1 and Brian M. Hicksa1

a1 Department of Psychology, University of Minnesota, Twin Cities Campus, Minneapolis, MN, USA


Background We hypothesized that gender differences in average levels on the internalizing and externalizing factors that account for co-morbidity among common psychopathological syndromes in both men and women account for gender differences in the prevalence of specific syndromes.

Method The latent structure of 11 syndromes was examined in a middle-aged (mean age=52.66 years, s.d.=5.82) sample of 2992 (37% men) members of the community-based Minnesota Twin Registry (MTR) assessed using 10 scales of the Psychiatric Diagnostic Screening Questionnaire (PDSQ) and an adult antisocial behavior scale. Confirmatory factorial invariance models were applied to a best-fitting, internalizing–externalizing model.

Results A ‘strong gender invariance model’ fit best, indicating that gender differences in the means of individual syndromes were well accounted for by gender differences in mean levels of internalizing and externalizing. Women exhibited higher mean levels of internalizing (d=0.23) and lower mean levels of externalizing (d=−0.52) than men.

Conclusions These findings suggest that risk factors for common mental disorders exhibiting gender differences may influence prevalence at the latent factor level. Future research may benefit from focusing on both the latent factor and individual syndrome levels in explaining gender differences in psychopathology.

(Received July 19 2006)

(Revised July 10 2007)

(Accepted July 17 2007)

(Online publication September 25 2007)


c1 Address for correspondence: M. D. Kramer or R. F. Krueger, Department of Psychology, University of Minnesota, 75 East River Road, Minneapolis, MN 55455, USA. (Email: or