Examining symptom expression as a function of symptom severity: item performance on the Hamilton Rating Scale for Depression.
Despite widespread use of the Hamilton Rating Scale for Depression (HRSD; M. Hamilton, 1960), questions have been raised concerning its psychometric properties. A nonparametric item response model was used to examine how the probability of observing a specific symptom of depression changes with increases in depressive severity in a sample of depressed adults. Results showed that options from a number of items on the HRSD did not vary as a function of severity and therefore should not be viewed as indicators of depressive severity. The extent to which symptoms are expressed as a function of depressive severity carries important implications for the use of the HRSD as a measure of severity and for the debate concerning construction of depression as a continuum. Results argue against viewing depression as a simple continuum.
Santor
D A
DA
Department of Psychology, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada. dsantor@is.dal.ca
Coyne
J C
JC
D000328:Adult; D003863:Depression / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D011581:Psychological Tests / Q000706:statistics & numerical data; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric