Major Depression Inventory (MDI)

The Major Depression Inventory is a self-rating depression scale with 12 questions. The questionnaire has previously been investigated in a Danish population. The scale contains the 10 ICD-10 (International Classification of Diseases)symptoms of depression and these symptoms are identical with the DSM-IV major depression symptoms with the exception of one symptom, low self-esteem, which in DSM-IV (Diagnostic and Statistical Manual of Mental Disorders) is incorporated in the symptom of guilt. On a six-point Likert scale, the individual items measure how much of the time the symptoms have been present during the last 14 days. The MDI is then scored according to specific guidelines and can be used as both a rating scale and a diagnostic instrument.

Research findings suggest that the MDI possesses good reliability and validity. Cuijpers and associates (2007) found that the test had good reliability, a substantial correlation with another measure of depressive symptoms, and acceptable specificity and sensitivity. Also, Forsell (2003) found that the MDI has high internal consistency. Furthermore, Olsen and colleagues (2003) found that the tool demonstrated adequate internal and external validity as a measure of depression severity.