 The MDI differs from many other self-report inventories, such as the Beck Depression Inventory (BDI), because it is able to generate an ICD-10 or DSM-IV diagnosis of clinical depression in addition to an estimate of symptom severity.Unlike many other similar instruments, the MDI is available free of charge and can be downloaded from the internet with a full manual and scoring instructions.This makes it an attractive option in epidemiological population surveys.