Depression is diagnosed through a comprehensive evaluation that includes a detailed medical history, physical examination, and psychological assessment. During the initial consultation, the healthcare provider will ask about symptoms such as persistent sadness, loss of interest in activities, changes in appetite and sleep patterns, fatigue, feelings of worthlessness or guilt, difficulty concentrating, and thoughts of death or suicide. The duration and severity of these symptoms are also considered, as depression is typically diagnosed when symptoms persist for at least two weeks and significantly impact daily functioning.

The psychological assessment may involve standardized questionnaires or rating scales, such as the Patient Health Questionnaire (PHQ-9) or the Beck Depression Inventory (BDI), which help quantify the severity of depression. The healthcare provider will also evaluate any potential medical conditions or medications that could contribute to depressive symptoms. In some cases, blood tests may be conducted to rule out underlying health issues such as thyroid disorders or vitamin deficiencies. A thorough and accurate diagnosis is essential for developing an effective treatment plan tailored to the individual's needs.