Major Depression Inventory

Major Depression Inventory (MDI) is a self-report mood questionnaire developed by the World Health Organization's Collaborating Centre in Mental Health. The primary purpose of the MDI is to assess the presence and severity of symptoms of depression as described in both the International Classification of Diseases (ICD-10) and the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). It is a widely used tool in both clinical and research settings.

Overview

The MDI consists of a series of 10 items, which evaluate core symptoms of depression such as low mood, lack of interest, lack of energy, feelings of guilt, and thoughts of death or suicide. Respondents are asked to rate how they have been feeling over the past two weeks on a 6-point scale ranging from 0 (at no time) to 5 (all the time). The MDI can be used to generate a score that indicates the severity of depression, and it can also be used to make a provisional diagnosis of depression according to ICD-10 or DSM-IV criteria.

Usage

The MDI is used in a variety of settings, including primary care, psychiatric outpatient clinics, and research studies. It can be administered by a healthcare professional or self-administered by the patient. The ease of use, combined with its ability to map onto diagnostic criteria, makes the MDI a valuable tool for screening and monitoring treatment outcomes in individuals with depression.

Scoring and Interpretation

The total score of the MDI is calculated by summing the scores of the 10 items. The maximum possible score is 50, with higher scores indicating more severe depression. Specific cut-off points have been established to categorize the severity of depression, ranging from normal to mild, moderate, and severe depression. Additionally, the MDI includes algorithms for diagnosing major depressive disorder according to ICD-10 and DSM-IV criteria, based on the pattern of responses across specific items.

Validation and Reliability

The MDI has been subjected to numerous validation studies across different populations and settings. It has been found to have good psychometric properties, including high internal consistency, reliability, and validity in identifying major depressive disorder. Its performance has been compared favorably with other established depression scales, such as the Hamilton Depression Rating Scale and the Beck Depression Inventory.

Advantages and Limitations

One of the main advantages of the MDI is its dual function as both a screening tool and a diagnostic instrument. It is also brief and easy to administer, making it suitable for busy clinical settings and for use in epidemiological studies. However, like all self-report instruments, the MDI's accuracy can be affected by the respondent's willingness to report symptoms honestly and by their level of insight into their condition.

Conclusion

The Major Depression Inventory is a valuable tool for the assessment of depression, offering a quick and reliable means of identifying individuals who may benefit from further evaluation or treatment. Its utility in both clinical practice and research underscores the importance of accessible and valid measures in the ongoing effort to address the global burden of depressive disorders.