Although research on the severity and prevalence of depression among lesbian, gay and bisexual (LGB) individuals is becoming increasingly... Show moreAlthough research on the severity and prevalence of depression among lesbian, gay and bisexual (LGB) individuals is becoming increasingly common, virtually no studies have examined differences in the experience of individual depressive symptoms in LGB individuals. Relatedly, research has not yet been done on whether depression measures function equivalently across sexual orientation. In this study, LGB men and women were compared with heterosexual men and women to assess the Differential Item Functioning of the Center for Epidemiological Studies Depression (CES-D) scale using moderated multiple regressions. Eight of the scale’s 20 items were found to function differently depending on the participants’ genders and sexual orientations, although the CES-D was shown to be an accurate measure of depression across gender and sexual orientation. The differences in individual items could not be explained by the variables proposed to explain them (e.g. race, social support, internalized heterosexism, etc.). Some of the item differences indicated differences in depression itself across gender and/or sexual orientation, although most indicated group differences unrelated to depression. The clinical and psychometric implications of these item differences are discussed. Ph.D. in Psychology, December 2014 Show less