Aims: This study examined the association between the Major Depression Inventory (MDI) and the Schedules for Clinical Assessment in Neuropsychiatry (SCAN).
Methodology: A questionnaire including the MDI was sent out to an adult population and was completed by a total of 10,448 persons. Psychiatrists used SCAN and interviewed a subsample (n=1093).
Results: The specificity of the MDI was 0.22, the sensitivity 0.67 and Kappa 0.25 when Major Depression according to SCAN was considered as the index of validity, and with all depressive disorders the specificity was 0.44, the sensitivity 0.51 and Kappa 0.33. Higher educated persons and those with reported disability were less likely to be false negatives. The sensitivity and specificity for different cut-off scores when using the MDI total score were calculated.
Conclusion: The result from this study suggests that, when MDI is used in population-based samples, cut-off scores rather than the algorithm for depression should be used. The optimal cut-off score must be chosen according to the aims of the study.