Psychological Medicine

Original Articles

Use of item response theory to understand differential functioning of DSM-IV major depression symptoms by race, ethnicity and gender

L. A. Uebelackera1 c1, D. Stronga1, L. M. Weinstocka1 and I. W. Millera1

a1 Warren Alpert Medical School of Brown University and Butler Hospital, Providence, RI, USA


Background Psychological literature and clinical lore suggest that there may be systematic differences in how various demographic groups experience depressive symptoms, particularly somatic symptoms. The aim of the current study was to use methods based on item response theory (IRT) to examine whether, when equating for levels of depression symptom severity, there are demographic differences in the likelihood of reporting DSM-IV depression symptoms.

Method We conducted a secondary analysis of a subset (n=13 753) of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) dataset, which includes a large epidemiological sample of English-speaking Americans. We compared data from women and men, Hispanics and non-Hispanic Whites, African Americans and Whites, Asian Americans and Whites, and American Indians and Whites.

Results There were few differences overall, although the differences that we did find were primarily limited to somatic symptoms, and particularly appetite and weight disturbance.

Conclusions For the most part, individuals responded similarly to the criteria used to diagnose major depression across gender and across English-speaking racial and ethnic groups in the USA.

(Received September 26 2007)

(Revised May 15 2008)

(Accepted May 17 2008)

(Online publication June 30 2008)


c1 Address for correspondence: Dr L. A. Uebelacker, Butler Hospital, 345 Blackstone Boulevard, Providence, RI 02906, USA. (Email: