Depression is a serious and common mental disorder that negatively impacts the way one acts, thinks, or feels. A depressed person experiences persistent sadness for no discernible reason and tends to lose their will to perform day-to-day activities or even to live. Clinical depression, if left untreated, can manifest itself in other physical and mental problems and impair a person’s performance at work or school. Depression is a curable disorder and can be diagnosed using a variety of tests.

What is a depression test?
Depression tests are screening tests entailing psychiatric evaluations, followed by physical and lab tests. They help a mental health professional determine whether one is suffering from clinical depression.

All doctors don’t follow a single standard depression test. A physician may run a series of tests to ensure one’s depression symptoms are not, in fact, a result of other health conditions like thyroid or vitamin D deficiency.

How do depression tests work?
Depression screening is often used as a first step in determining whether a physician should inquire more about an individual’s mental health. It is in a common format of a questionnaire, either asked orally, on paper, or online.

A professional asks a few straightforward questions about a patient’s mood, behavior, and recurring symptoms in a defined time period. This process helps him to determine the severity of depression and decide whether additional physical assessments or lab tests are required.

How accurate are depression tests?
A depression test with a questionnaire doesn’t consider other potential explanations for a person’s answers. For example, a person may report loss of appetite, but diabetes or hypothyroidism may be the cause of it rather than depression.

So, the answers alone are insufficient to identify whether someone is depressed or not. A professional needs to probe the case further and build a complete diagnosis to rule out other conditions.

What are the types of depression tests?
Broadly, depression can be diagnosed using one or more of the below-listed methods:

Psychiatric evaluation
Psychiatric evaluations inquire about one’s feelings, thoughts, and behavior patterns using questionnaires. These tools are widely used to indicate whether an individual has symptoms of depression that may require professional intervention.

The most common ones are:

• Patient Health Questionnaire-9 (PHQ-9)
  PHQ-9 contains nine self-report items that weigh one’s depression symptoms in the past two weeks. Based on the result, if one is diagnosed with depression, one will be asked the tenth question. Each item is rated on a four-point scale, from 0 (“not at all”) to 3 (“almost all of the days”).
• PHQ-9 for Adolescents (PHQ-A)
  A variation of the above questionnaire, this one is specially modified for adolescents.
• Zung Self-Rating Depression Scales
  Designed by Duke University psychiatrist William W.K. Zung, this test has been translated into Arabic, Azerbaijani, Dutch, German, Portuguese, and Spanish. It has about 20 self-report items describing one’s behavior in the past several days.
• EQ-5D
  Designed by a group of European researchers, the EuroQol Group, this test has two versions, one for adults aged 16 and above, and another for youngsters below 15. It is available worldwide in multiple languages.
• Beck Depression Inventory (BDI)
  Created by psychiatrist Aaron Beck, this is a 10 minutes test with an inventory of 21 self-report items in the format of multiple choice questions. It can be taken by anyone aged between 13 and 80.
• Center for Epidemiologic Studies Depression Scale (CES-D)
  Designed for the general public, this test contains 20 self-report items that register depression symptoms in the past week. Each item is rated on a four-point scale, from 0 (“rarely or none of the time”) to 3 (“most or all of the time”). It can be taken by kids as young as six and adults.
• Major Depression Inventory (MDI)
  MDI was developed by the World Health Organization’s Collaborating Center in Mental Health. With ten self-report items, one has to rate how frequently one experiences various symptoms over the previous two weeks, ranging from “never” to “all the time.”
• Geriatric Depression Scale
  This test, used for older adults, has about 25 self-report items describing one’s discomfort.
• Edinburgh Postnatal Depression Scale (EPDS)
  This test is designed for postpartum and pregnant women and evaluates their symptoms in the past week.
• Geriatric Depression Scale (GDS)
  Designed for older adults, it contains 30 yes-or-no questions that take less than 10 minutes to complete.
• Hamilton Rating Scale for Depression (HRSD)
  This test is also a multiple choice questionnaire with 21 self-report items measured either on a 3-point or 5-point scale.

There are also online questionnaires designed specifically for children and adolescents aged between 6 and 18. Some of the common ones include:

• Children’s Depression Inventory (CDI)
• Child Behavior Checklist (CBCL)
• Children’s Depression Rating Scale (CDRS)
• Behavior Assessment System for Children (BASC)

If one’s test score indicates depression, one can seek further assistance. To make a precise diagnosis, a mental health expert will speak to you about your responses, elicit more information, and request other tests, as mentioned below.

Physical examination
The medical health expert might examine one’s overall health to determine if they are depressed.

Lab tests
There may also be some blood tests conducted to assess hormone levels and other lab tests to check kidney and liver health, blood sugar level, calcium and magnesium levels, and folate and vitamin deficiencies. Any discrepancies in these levels can show symptoms similar to depression.

Where to take depression tests?
Depression screenings for psychiatric evaluation are easily available online. Many websites offer free screening tests that allow individuals to complete in the privacy of their own homes.

Depression treatment can be as complicated as the illness itself. What works well for one individual may not work at all for another. So getting expert help is always advisable.