**2.4.2 Beck's Depression Inventory (BDI) (Beck, 1961)**

Beck's Depression Inventory is a 21-item self-report rating inventory measuring characteristic attitudes and symptoms of depression. The total score ranges between 0 and 63; scores below 14 are considered normal, scores from 14 to19 indicate mild to moderate depression, scores from 20 to 28, moderate to severe depression, and scores higher than 28 are indicative of severe depression. This questionnaire is regularly used as a complementary measure.
