IDS-C and IDS-SR: Psychometric properties in depressed in-patients

Sixty-eight depressed in-patients were assessed at admission (DO), and afte r 5 days (D5), ten days (D10) and 28 days (D28) of antidepressant treatment , with the Inventory for Depressive Symptomatology-Clinician (IDS-C) and th e Inventory for Depressive Symptomatology-Self-Rated (IDS-SR) (Rush et al., 1986),: the Montgomery and Asberg Depression Rating Scale (MADRS) (Montgom ery and Asberg, 1979) and the depression factor of the Symptom Check List ( SCL-90R) (Derogatis, 1977), in order to assess IDS-C and IDS-SR psychometri c properties in depressed in-patients and to compare IDS-C to MADRS and IDS -SR to the SCL-90R depression factor. Most of the LDS-C and IDS-SR items we re significantly correlated to the final score and the Cronbach alpha coeff icients were high (0.75 for the IDS-C and 0.79 for the IDS-SR). Principal C omponent Analyses (PCA) showed three factors for both IDS-C and IDS-SR: 'de pression', 'anxiety/arousal' and 'sleep/appetite'. These results suggest sa tisfactory internal consistency of IDS-C and IDS-SR. Concurrent validity of the IDS-C with the MADRS was high (r = 0.81), as well as concurrent validi ty:of the IDS-SR with the SCL-90R depression factor (r = 0.84). Concerning sensitivity to change, the four scales were able to discriminate between di fferent levels of severity of depression. Moreover, considering paired t-te sts on score changes, LDS-C sensitivity to change may be higher than MADRS sensitivity to change, this phenomenon being related to the number of items and degrees but not to the item contents, Contrary to TDS-C and MADRS, IDS -SR and SCL-90R depression factor were not different in terms of sensitivit y to change. Finally, psychometric properties of IDS-C and IDS-SR in depres sed in-patients are satisfactory and close to those obtained in-depressed o ut-patients. The high sensitivity to change of the IDS-C may be an advantag e for this scale as compared to the MADRS, especially in antidepressant dru g trials. (C) 1999 Elsevier Science BN. All rights reserved.