The inventory to diagnose depression, lifetime version.

The lifetime version of the Inventory to Diagnose Depression (IDDL) is a 22-item self-report scale designed to diagnose a lifetime history of DSM-III major depressive disorder (MDD). One hundred and sixty-four first-degree relatives of healthy control probands completed the IDDL and were interviewed with the Diagnostic Interview Schedule (DIS). The IDDL had good internal consistency (Cronbach's alpha = 0.92), split-half reliability (Spearman-Brown coefficient = 0.90), and all of the item total correlations were significant. The lifetime prevalence of MDD was nonsignificantly higher in the IDDL than the DIS (14.8% vs. 11.7%). Using the DIS as the criterion measure, the sensitivity of the IDDL was 74% and its specificity was 93% and the chance corrected agreement between the two measures was kappa = 0.60.