Your MDI score reflects the severity of depressive symptoms you have experienced over the past two weeks. A score below 20 suggests no or minimal depression. A score of 20 to 24 indicates mild depression, meaning you may be experiencing some low mood and reduced enjoyment but can still function in daily activities. A score of 25 to 29 indicates moderate depression, where symptoms are more pervasive and likely interfering with work, relationships, or daily routines. A score of 30 or above indicates severe depression, suggesting significant impairment that typically warrants prompt clinical attention.

The MDI can also be used diagnostically by mapping specific item responses to ICD-10 criteria for depressive episodes. For a diagnostic interpretation, at least two of the three core symptoms (depressed mood, loss of interest, fatigue) must score 4 or higher, along with additional qualifying symptoms. Your clinician can help determine whether your responses meet the threshold for a formal ICD-10 diagnosis of depression.

The MDI is appropriate for routine depression screening in primary care, mental health clinics, and research settings. It is particularly useful in international contexts because it is freely available and WHO-endorsed, eliminating licensing barriers. Clinicians may administer it at initial intake visits, during follow-up appointments to track treatment response, or as part of population health screening programs.

The MDI is also valuable when an ICD-10-aligned diagnostic assessment is preferred over a DSM-based tool. Because it can serve both as a continuous severity measure and as a diagnostic algorithm, it offers flexibility that some other depression instruments lack. It is suitable for adults in both clinical and community settings.

The MDI is a self-report instrument and depends on the respondent's insight, honesty, and literacy. Patients with severe depression, cognitive impairment, or psychotic features may underreport or have difficulty completing the questionnaire accurately. It does not replace a comprehensive clinical interview for diagnosing depression.

The MDI does not assess anxiety, bipolar features, or psychotic symptoms, which frequently co-occur with depression. A high MDI score should prompt further evaluation to rule out other psychiatric conditions. Additionally, somatic symptoms captured by the MDI (fatigue, sleep changes, appetite changes) can be caused by medical illnesses, potentially inflating scores in medically ill populations.

While the MDI has been validated in multiple languages and populations, cultural factors can influence how individuals interpret and report mood symptoms. Clinicians should consider the patient's cultural background when interpreting results.