The major depression inventory, or MDI, is a self-administered questionnaire used for identifying and measuring the severity of depression. The questionnaire asks individuals to rate various aspects of their moods over a period of time, often two weeks. Subjects are prompted to indicate if they've felt a certain way or acted in a certain manner "all the time," "not at all," or a variety of other possibilities in between over the course of that time period. The term "major depression inventory" usually refers to a specific questionnaire of this type developed by the World Health Organization. There are, however, many other self-administered questionnaires that exist for the same purpose and that tend to differ only in small details.
Questions on the major depression inventory tend to focus primarily on moods and habits. The inventory tends to prompt people to indicate how often they have felt sad, lacking in energy, guilty, or lacking in purpose over a given period of time. The major depression inventory also questions people about habits such as eating, sleeping, and recreation. People taking the questionnaire are asked, for instance, to indicate how often in the last two weeks they have felt like life wasn't worth living and how often they have had trouble sleeping.
One of the major benefits of the major depression inventory, particularly the one published by the World Health Organization, is its widespread availability and ease of use. The questionnaire is available online in many different languages and can be downloaded and printed. It also has easy-to-follow scoring instructions, and some versions simply involve filling out a form and scoring it online. The test can be scored to provide results in a manner that conforms to one of a variety of widely-used diagnostic systems. Results of this self-administered questionnaire can also be collected in order to gather information about the mental health of a population.
While the major depression inventory can provide a good indication of whether or not one suffers from depression and of the relative severity of that depression, one should seek professional help with serious concerns about major mood disturbances. A mental health professional can provide a more nuanced diagnosis than the major depression inventory and can also suggest and provide treatment. In some cases, depression-like symptoms can be caused by disorders that go beyond depression. A mental health professional can examine such symptoms can determine the best options for coping and, hopefully, recovering.