A doctor can rule out other conditions that may cause depression with a physical examination, a personal interview, and lab tests. The doctor will also do a complete diagnostic evaluation, discussing any family history of depression or other mental illness.
Before you go to the doctor, you may want to try the quiz/questionnaire at home first – your doctor may use these questionnaires as well, as the depression screening instruments that measure the presence and severity of depression symptoms. A depression screening, also called a depression test, helps find out if you have depression.
Currently, following the questions/interviews that doctors will normally ask the patients, there have been multiple standardized, commonly-used questionnaires to help the doctor or the patient to quickly make an assessment.
The Patient Health Questionnaire-9 (PHQ-9)
PHQ-9 is a 9-item self-administered diagnostic screening and severity tool based on current diagnostic criteria for major depression. The PHQ-9 is intended to be used by clinicians or researchers in primary care settings, but now, it has become available for people to quickly screen themselves online.