The quick inventory of depressive symptomatology (clinician and self-report versions) in patients with bipolar disorder

Introduction: The clinical and self-report versions of the Quick Inventory of Depressive Symptomatology (QIDS-C16 and QIDS-SR16) have been well studied in patients with major depressive disorder and in one recent study using patients with bipolar disorder. This article examines these measures in a second sample of 141 outpatients with bipolar disorder in different phases of the illness. Methods: At baseline, 61 patients were depressed and 30 were euthymic; at exit, 50 were depressed and 52 were euthymic. The remaining patients (at baseline or exit) were in either a manic or mixed phase and were pooled for statistical reasons. Results: Similar results were found for the QIDS-C16 and QIDS-SR16. Scores were reasonably reliable to the extent that variability within groups permitted. As expected, euthymic patients showed less depressive symptomatology than depressed patients. Sad mood and general interest were the most discriminating symptoms between depressed and euthymic phases. Changes in illness phase (baseline to exit) were associated with substantial changes in scores. The relation of individual depressive symptoms to the overall level of depression was consistent across phases. Conclusion: Both the QIDS-SR16 and QIDS-C16 are suitable measures of depressive symptoms in patients with bipolar disorder.