Reliability, validity, and factor structure of the geriatric depression scale in Turkish elderly: Are there different factor structures for differentcultures?

The purpose of this study was to examine the Geriatric Depression Scale (GD S) translated into Turkish for its reliability, discriminant validity, and factor structure in a sample of 276 community-dwelling elderly and 30 patie nts with major depression. One item (Item 5) was discovered to have concept ual difficulty for Turkish elderly and was transformed to negative form. It em 2 was transformed to positive form to keep the number of positive and ne gative items equal to that in the original GDS. A reasonable time stability with 1-week interval (r:.74) and a high level of internal consistency (alp ha = .91) were observed. Student's t test resulted in a significant discrim inant validity for the scale total score. Factor study with principal compo nent analysis and varimax rotation gave rise to a structure with seven fact ors. Results of the same analysis with two factors were found to be easier to interpret. The first factor was composed of 19 items reflecting "depress ive affect and thought content." The other 11 items representing "decrease in motivation and cognitive functions" loaded in the second factor. In conc lusion, the Turkish GDS was found to have reasonable time reliability, high internal consistency, and discriminant validity for Turkish elderly. Its t wo-factor structure can be used as an informative instrument for epidemiolo gical studies, reflecting two main dimensions of depression in the elderly.