There’s no blood test or brain scan that can diagnose depression—but clinicians use structured assessments, interviews, and screening tools to identify it accurately. Diagnosis relies on understanding your symptoms, their duration, and how they affect your life.

Step 1: Clinical Interview

A doctor or mental health professional will ask detailed questions about:

• Your mood (sadness, hopelessness, irritability)
• Sleep, appetite, and energy levels
• Concentration and decision-making
• Feelings of worthlessness or guilt
• Thoughts of death or suicide
• How long symptoms have lasted
• Impact on work, relationships, and daily functioning

They’ll also rule out medical causes (like thyroid disorders, vitamin deficiencies, or chronic illness) that can mimic depression.

Step 2: Standardized Screening Tools

Professionals often use brief, validated questionnaires such as:

• PHQ-9 (Patient Health Questionnaire-9): Rates how often you’ve experienced core depression symptoms over the past two weeks.
• Beck Depression Inventory (BDI): Measures severity of symptoms like guilt, fatigue, and loss of interest.
• Hamilton Depression Rating Scale (HDRS): Used more in clinical settings to track treatment progress.

These aren’t diagnostic on their own—but they help quantify symptoms and guide care.

Step 3: Diagnostic Criteria (DSM-5)

To be diagnosed with Major Depressive Disorder, you must have:

• At least 5 of 9 key symptoms (including depressed mood or loss of interest)
• Symptoms present most of the day, nearly every day, for at least 2 weeks
• Clear impairment in social, occupational, or other important areas
• Symptoms not due to drugs, medical illness, or bereavement alone

Step 4: Physical Tests (To Rule Out Other Causes)

Your doctor may order:

• Blood tests (thyroid panel, vitamin D/B12, complete blood count)
• Urine tests (to check for infections or substance use)

These ensure depression isn’t secondary to another condition.

Why Early Screening Matters

Depression is highly treatable—especially when caught early. You don’t need to “hit rock bottom” to seek help. If you’ve felt “off” for more than two weeks, talking to a professional isn’t overreacting—it’s self-care.

Testing for depression isn’t about labeling—it’s about understanding your pain and unlocking the right support. And that understanding is the first real step toward healing.