blood test depression

What is the blood test for depression and mental health conditions?

Typically, a blood test is ordered by your physician, usually during a physical examination. This blood/lab test is ordered to see if there are any abnormalities in your blood work that can cause various health problems. One of these problems can be depression. Along with the blood work, your doctor can determine if you have depression or any other mental health condition, such as bipolar disorder or manic-depressive illness by asking you specific questions relating to mental health and moving from there, usually by doing some sort of physical examination. The blood tests serve as a helpful indicator by showing if there are any physical conditions that correspond to common symptoms of depression.

Physicians primarily use these blood tests in this way to check for anemia (a lack of red blood cells carrying oxygen to and from the brain) and thyroid problems (your thyroid helps to control hormone levels throughout the body). These tests also check calcium levels and vitamin D levels, among many other vitamin and hormone levels.

Your physician may also use these blood tests and lab reports to check your levels of electrolytes, toxicology screening (if there are any toxic chemicals in the body), liver function, and kidney function. The liver and kidneys help to flush out depression medications, so if either one or both organs are somehow impaired, the depression medications can build up in the body, which can become dangerous.

There is also evidence that shows that psychological stress lowers the levels of a particular protein called mature brain-derived neurotrophic factor (mBDNF), and lower levels of mBDNF are shown to be associated with symptoms of depression.

How does the blood test work, and what are its benefits?

The blood test that is used to find the biomarker for diagnosing depression was developed as a screening method and is more objective at diagnosing depression. The diagnosis would be completely unbiased (nondiscriminatory). This test has a very rapid turn-around time, unlike other tests, which are rather slow and on the more expensive side, both of which reduces the validity and viability of the other tests.

It has been shown and proven that those with depression have lower levels of ethanolamine phosphate in their blood, which is crucial in regulating the balance of hormone levels in the brain and how neurons communicate with each other throughout the brain.

The way that depression develops in people, as well as populations of people, can impact regular bodily functions. This test shows that depression has a serious effect on metabolism, the immune system and nervous system, as well as the hypothalamus, pituitary gland, and adrenal glands. One of the major benefits of this test is that, because of the speed with which it produces results, it can be used to refer clients to specialists who work primarily in this line of work—those who specialize in treating depression. Essentially, this blood test will be used to help physicians make a proper diagnosis and refer out to specialists for clients/patients to get the proper treatment and help they need.

Who should consider taking a blood test for depression and mental health conditions?

There are many different potential symptoms of depression, some of which can be slowly developing or less noticeable. Depression can cause hormone imbalances and subsequently create numerous health issues, and those that are experiencing these common symptoms of depression should consult with their doctor or physician and consider getting a blood test.

  • Difficulty concentrating, forgetfulness, decision making, “brain fog”: Depression can have a significant effect on brain activity. If you are feeling increasingly forgetful or noticing changes in your daily functioning, along with any of the other symptoms listed, this may be an indication of depression.
  • Fatigue, insomnia, trouble sleeping: Drastic changes in sleeping habits or difficulty sleeping can come as a symptom of depression. Similarly, feeling significantly fatigued or restless throughout the day, even while maintaining healthy sleeping patterns, is another health issue that should be checked.
  • Loss of appetite, overeating, dieting changes, digestive issues: Depression affects patients’ metabolism and hormone levels, which in turn affects eating habits and how our bodies receive and respond to food, nutrients, and vitamins. Liver function and kidney function can also be impaired as a result of depression or depression medication.
  • Body aches and pains, general discomfort, or illness: As mentioned, depression can have a serious impact on one’s physical health, and these health issues are related to hormone imbalances and the effect depression can have on the body’s immune system, nervous system, and endocrine system.
  • Heightened feelings of sadness, emptiness, irritability, pessimism
  • Mood swings, bipolar disorder, anxiety, suicidal thoughts or suicide attempts: Significant behavioral changes such as these and noticeable emotional distress are both common symptoms of depression. Substance abuse/addiction, newly developed or increased dependency on substances, and significant changes in one’s reaction to medication should all be monitored as well. It is important to consider the association between mood disorders and other mental health issues and depression.

Anyone that has experienced or is currently experiencing these symptoms should consult with their doctor or physician to consider getting a blood test. A self-report or a health care professional’s typical clinical diagnosis of depression, mood disorders, and other mental health issues can sometimes be unreliable or inaccurate, whereas a blood test can be helpful in developing a precise diagnosis and thus creating a more personalized medication and treatment process.

blood test for depression

Are there any risks associated with getting a blood test for depression and mental health conditions?

Generally, blood tests are very safe, and the health care professionals follow a strict set of guidelines regarding blood work and the handling, storage, and disposal of needles and blood samples. However, the professionals taking your blood test should be made aware of any preexisting health conditions, blood thinner medications, or susceptibility to bruising or infection that a patient may have. Patients with existing conditions or health issues should consult with their doctor before getting a blood test. Mild bruising around the area where the blood is drawn is common, but some people may be at risk of severe or lasting bruising and this issue should be monitored.

Anyone getting blood work done should notify their doctor or physician if they have any existing bloodborne diseases. Again, because of the regulations health care professionals must follow when taking blood tests, the risk of infection is low.

Fainting, dizziness, and nausea are all commonly experienced by people that have a fear of needles, injections, or blood. If you have previously had problems with blood work or injections, or you are feeling faint or uneasy before, during, or after your blood test, notify your doctor and they will be able to assist you.

What are the next steps if someone decides to get a blood test for depression and mental health conditions?

After receiving the blood test results, your doctor should be able to develop a diagnosis and recommend the proper treatment and medication based on the blood test. Along with the blood test, additional questioning and/or a physical examination by your doctor will help to create a precise diagnosis of possible medical conditions and mental health issues. It is important that patients follow the recommendations of trusted health care professionals.



2. Verma, R. K., Kaur, S., & David, S. R. (2012, November). An instant diagnosis for depression by Blood Test. Journal of clinical and diagnostic research : JCDR. Retrieved February 9, 2022, from

3. Bruce, D. F. F. (2020, September 28). Depression tests — blood tests, screening, and other tests. WebMD. Retrieved February 9, 2022, from