If you plan to see your doctor because of a constant low mood, here is information on the types of tests your doctor may order.
First, keep in mind that not every test is a ” depression test .” Some tests are not used to diagnose clinical depression, but to rule out other serious medical conditions that can cause similar symptoms.
In most cases, your doctor will perform a physical exam and order specific lab tests to make sure your symptoms of depression are not related to a condition such as thyroid disease , vitamin D deficiency, or another medical problem.
If your symptoms are related to another serious illness, treating that illness can also help relieve depression.
Again, the goal with a physical exam is usually to rule out another medical cause for the depression. When performing the physical examination, the physician may focus primarily on the neurological and endocrine systems.
The doctor will try to identify any major health problems that may be contributing to the symptoms of clinical depression. For example, hypothyroidism, caused by an underactive thyroid gland, is the most common medical condition associated with depressive symptoms.
Other endocrine disorders associated with depression include hyperthyroidism , caused by an overactive thyroid, and Cushing’s disease, a disorder of the adrenal gland.
Many diseases and injuries of the central nervous system can also lead to depression. For example, depression may be associated with any of the following conditions:
- Tumors of the central nervous system.
- Head trauma
- Multiple sclerosis.
- Various cancers (pancreas, prostate, breast).
Corticosteroid medications, such as prednisone , that people take for conditions like rheumatoid arthritis or asthma, are also associated with depression.
Other drugs, including illegal steroids and amphetamines and over-the-counter appetite suppressants, can cause withdrawal depression.
Your doctor can usually determine if you have depression by asking specific questions and doing a physical exam. However, your doctor may order lab tests to rule out other diagnoses.
Your doctor will likely run blood tests to check for medical conditions that can cause depressive symptoms. He or she will use blood tests to check for anemia, thyroid or possibly other hormones, and sometimes calcium and vitamin D levels.
Other test methods
The doctor may include other standard tests as part of the initial physical exam. These may include blood tests to monitor electrolytes, liver function, toxicology, and kidney function.
Because the kidneys and liver are responsible for the removal of depression medications, deterioration of either of these two organs can cause the medications to build up in the body.
Other tests can sometimes include:
- CT or MRI scan of the brain to rule out serious diseases, such as a brain tumor.
- Electrocardiogram (ECG) to diagnose some heart problems.
- Electroencephalogram (EEG) to record the electrical activity of the brain.
Screening for depression
After analyzing your mood and how it affects your life, your doctor may also ask you questions that are specifically used to screen for depression.
It is important to note that the inventories and questionnaires that the doctor can use are only part of the medical process to diagnose depression.
However, these tests can sometimes give your doctor a better idea of your mood. He or she can use them to make a diagnosis with more certainty.
An example of a screening test is a two-part questionnaire that has been shown to be highly reliable in identifying the likelihood of depression. When you take this test, you will be asked to answer two questions:
- In the past month, has feeling depressed or hopeless bothered you?
- In the past month, has little interest or pleasure in doing things bothered you?
Your answer to the two questions will determine what the doctor will do next. Your doctor may ask you additional questions to help confirm a diagnosis of depression.
Or if your answers indicate that you do not have depression, your doctor may review your symptoms again to continue the effort to find the cause.
Studies show that these two questions, especially when used with another test as part of the screening process, are very effective tools for detecting most cases of depression.
Your doctor may use other depression screening tools that measure the presence and severity of depression symptoms. Examples include:
- The Patient Health Questionnaire-9 (PHQ-9): A 9-item self-administered severity and assessment tool based on current diagnostic criteria for major depression.
- Beck Depression Inventory (BDI): A 21-question, multiple-choice self-report that measures the severity of symptoms and feelings of depression.
- Zung’s Self-Rating Depression Scale: A short survey that measures the level of depression, ranging from normal to severely depressed.
- Center for Epidemiological Studies-Depression Scale (CEE-ED): an instrument that allows patients to evaluate their feelings, behavior and perspectives from the previous week.
- Hamilton Scale for Depression, originally abbreviated HAM-D: A multiple-choice questionnaire that clinicians can use to assess the severity of a patient’s depression.
When you take an exam or inventory, you may feel uncomfortable responding honestly to questions or statements that are made.
The person administering the test will ask you about depression and your mood, cognition, and physical feelings of depression, such as low energy, sleep disorders, and sexual problems. Try to be as honest as you can when evaluating your symptoms.
Questionnaires and assessment tools can help a mental health professional make a diagnosis, but rating scales themselves are not a substitute for a clinical diagnosis made from a thorough interview.
Once your doctor has made an accurate diagnosis, he or she will be able to prescribe an effective treatment.
If the diagnosis is depression
Depression is treatable. Consequently, a diagnosis of depression can start you on the path to a healthier life without feelings of helplessness, hopelessness, and worthlessness.
Once your doctor makes a diagnosis of depression, you must follow the treatment program to get better. It is important to take your medications as prescribed.
You should also continue to make lifestyle changes and work with a psychotherapist if that is what your doctor recommends. Millions of people with depression suffer unnecessarily because they do not receive professional help that begins with a doctor’s diagnosis.