Medline ® Abstract for Reference 46

The 16-item Quick Inventory of Depressive Symptomatology (QIDS), a new measure of depressive symptom severity derived from the 30-item Inventory of Depressive Symptomatology (IDS), is available in both self-report (QIDS-SR(16)) and clinician-rated (QIDS-C(16)) formats. This report evaluates and compares the psychometric properties of the QIDS-SR(16) in relation to the IDS-SR(30) and the 24-item Hamilton Rating Scale for Depression (HAM-D(24)) in 596 adult outpatients treated for chronic nonpsychotic, major depressive disorder. Internal consistency was high for the QIDS-SR(16) (Cronbach's alpha =.86), the IDS-SR(30) (Cronbach's alpha =.92), and the HAM-D(24) (Cronbach's alpha =.88). QIDS-SR(16) total scores were highly correlated with IDS-SR(30) (.96) and HAM-D(24) (.86) total scores. Item-total correlations revealed that several similar items were highly correlated with both QIDS-SR(16) and IDS-SR(30) total scores. Roughly 1.3 times the QIDS-SR(16) total score is predictive of the HAM-D(17) (17-item version of the HAM-D) total score. The QIDS-SR(16) was as sensitive to symptom change as the IDS-SR(30) and HAM-D(24), indicating high concurrent validity for all three scales. The QIDS-SR(16) has highly acceptable psychometric properties, which supports the usefulness of this brief rating of depressive symptom severity in both clinical and research settings.