Your doctor will ask about your symptoms and past health. Your doctor may search for physical causes of depression. These findings will be used to make the diagnosis. There is no single test to do this.

You will have a:

• Physical exam—Certain medicines and health conditions can cause the same symptoms. Your doctor can rule these out. The most common ways are with a physical exam, questionnaires, and lab tests. This may involve tests to see if you have problems with your speech, thought patterns, or memory.
• Psychological exam—A mental health expert can give you this exam. You may take a special screening test. These tests don’t provide all the answers. They must also consider your situation and how these problems are affecting you.
• You may also be tested for other mental health problems. These can happen in people that have depression. These may be alcohol use disorder, substance use disorder, or problems with anxiety or mania.

A diagnosis is based on:

• Having symptoms for 2 weeks or more
• How many days a week you feel them—almost daily
• How many symptoms you have—5 or more
• What symptoms you have

You will be asked about your symptoms:

• When they started
• What brings them on
• How severe they are
• How much they keep you from going to work or school
• If they come with pain
• If you've had them before, if they were treated, and, if so, how
• If you have thoughts of self-harm or suicide
• Other people in your family with the same problems
• If they bother your sleep patterns