How Is Depression Diagnosed?
Depression is often diagnosed through a combination of lab tests and simply talking to a patient.
To effectively diagnose and treat depression, the doctor must hear about specific symptoms of depression. They may use a series of standard questions to screen for depression. While a physical examination will reveal a patient's overall state of health, by talking with a patient, a doctor can learn about other things that are relevant to making a depression diagnosis. A patient, for example, can report on such things as daily moods, behaviors, and lifestyle habits.
A depression diagnosis is often difficult to make because clinical depression can show up in so many different ways. For example, some clinically depressed people seem to withdraw into a state of apathy. Others may become irritable or even agitated. Eating and sleeping patterns can be exaggerated. Clinical depression may cause someone to sleep or eat to excess, or almost eliminate those activities.
Observable or behavioral symptoms of clinical depression also may sometimes be minimal despite profound inner turmoil. Depression can be an all-encompassing disorder, and it affects a person's body, feelings, thoughts, and behaviors in varying ways.
Types of depression your doctor may look for
It used to be that all mood disorders were lumped together. Now, a doctor will make a distinction about the particular disorder or subtype of depression that a patient has. For example, a doctor will determine whether a patient has major depression, chronic depression including dysthymia, seasonal affective disorder (SAD), bipolar disorder, or some other type of clinical depression.
Diagnosing Depression and the Physical Exam
Your doctor may include standard tests as part of the initial physical exam. Among them may be blood tests to check electrolytes, liver function, toxicology screening, and kidney function. Because the kidneys and liver are responsible for the elimination of depression medications, impairment to either of these two organs may cause the drugs to accumulate in the body.
Other tests may sometimes include:
- CT scan or MRI of the brain to rule out serious illnesses such as a brain tumor
- Electrocardiogram (EKG) to diagnose some heart problems
- Electroencephalogram (EEG) to record electrical activity of the brain
Depression Screening Tests
After discussing your mood and the way it affects your life, your doctor may also ask you questions that are used specifically to screen for depression. The inventories and questionnaires the doctor may use are just one part of the medical process of diagnosing depression. These tests, however, can sometimes give your doctor better insight into your mood. They can use them to make a diagnosis with more certainty.
One 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:
- During the past month, have you been bothered by feeling down, depressed, or hopeless?
- During the past month, have you been bothered by little interest or pleasure in doing things?
Your answer to the two questions will determine what the doctor does next. The doctor may ask you additional questions to help confirm a diagnosis of depression. Or if your answers indicate you do not have depression, the 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 assessment process, are highly effective tools for detecting most cases of depression.
Your doctor may use other depression screening instruments that measure the presence and severity of depression symptoms. Examples include:
- The Patient Health Questionnaire-9 (PHQ-9), a nine-item, self-administered diagnostic screening and severity 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 depression symptoms and feelings
- Zung Self-Rating Depression Scale, a short survey that measures the level of depression, ranging from normal to severely depressed
- Center for Epidemiologic Studies-Depression Scale (CES-D), an instrument that allows patients to evaluate their feelings, behavior, and outlook from the previous week
- Hamilton Rating Scale for Depression (HRSD), also known as the Hamilton Depression Rating Scale (HDRS) or HAM-D, a multiple-choice questionnaire that doctors may use to rate the severity of a patient's depression
When you take a test or inventory, you may feel uncomfortable responding honestly to questions or statements that are made. The person who administers the test will be asking about depression and mood, depression and cognition, and the physical feelings of depression such as lack of energy, sleep disturbance, and sexual problems. Be as honest as you can when assessing your symptoms. Questionnaires and screening tools can help a mental health professional in making a diagnosis, but rating scales in themselves are not a substitute for a clinical diagnosis made from a thorough interview. Once your doctor has made an accurate diagnosis, they can then prescribe an effective treatment.
What Does the Doctor Look for to Make a Depression Diagnosis?
Your doctor will evaluate your symptoms, including how long you've had them, when they started, and how they were treated. They'll ask about the way you feel, including whether you have any symptoms of depression such as:
- Sadness or depressed mood most of the day or almost every day
- Loss of enjoyment in things that were once pleasurable
- Major change in weight (gain or loss of more than 5% of weight within a month) or appetite
- Insomnia or excessive sleep almost every day
- Physical restlessness or sense of being run-down that others can notice
- Fatigue or loss of energy almost every day
- Feelings of hopelessness or worthlessness or excessive guilt almost every day
- Problems with concentration or making decisions almost every day
- Recurring thoughts of death or suicide, suicide plan, or suicide attempt
How Can Depression Symptoms Lead to a Depression Diagnosis?
To be diagnosed with major depression, you must have at least five of the symptoms listed above with at least one of the first two nearly daily for at least 2 weeks.
Depression symptoms can last weeks, months, or sometimes years. They can affect personality and interfere with social relationships and work habits, potentially making it difficult for others to have empathy for you. Some symptoms are so disabling that they interfere significantly with your ability to function. In very severe cases, people with depression may be unable to eat, maintain their hygiene, or even get out of bed.
Episodes may happen only once in a lifetime or may be recurrent, chronic, or longstanding. In some cases, they seem to last forever. Symptoms may appear to be precipitated by life crises. At other times, they may seem to happen at random.
Clinical depression commonly goes along with other medical illnesses such as heart disease or cancer and worsens the prognosis for these illnesses.
Are There Physical Signs of Depression?
Yes. In fact, a great many people with depression come to their doctor first with only physical issues. You might notice:
- Back pain
- Joint pain
- Limb pain
- Gut problems (digestion issues and belly pain)
- Constant tiredness
- Sleep problems
- Slowing of physical movement and thinking
You might notice these symptoms even before you notice the mental health symptoms of depression, or you might notice them at the same time. Your doctor can help you figure out the source of your symptoms.
How Can I Help the Doctor Make a Proper Diagnosis?
Before your appointment, write down your concerns about depression and specific symptoms of depression you might have. It’s also helpful to get an in-depth family history from relatives before meeting with your doctor. This information can help the doctor make an accurate diagnosis and ensure effective treatment. Before your visit, think about and write down:
- Your mental and physical health concerns
- Symptoms you've noticed
- Unusual behaviors you've had
- Past illnesses
- Your family history of depression
- Medications you’re taking now and in the past, including both prescribed and over-the-counter medications
- Unusual side effects of medications you are taking or have taken
- Natural dietary supplements you’re taking
- Your lifestyle habits (exercise, diet, smoking, alcohol consumption, drug use)
- Your sleep habits
- Causes of stress in your life (marriage, work, social)
- Questions you have about depression and depression medications
How Do I Know When to Seek Help?
The biggest hurdle to diagnosing and treating depression is recognizing that someone has it. Unfortunately, about half of the people who have depression never get diagnosed or treated. And not getting treatment can be life threatening: More than 10% of people who have depression take their own lives.
When depression is hurting your life, such as causing trouble with relationships, work issues, or family disputes, and there isn't a clear solution to these problems, you should seek help to keep things from getting worse, especially if these feelings last for any length of time.
If you or someone you know is having suicidal thoughts or feelings, call 911 or go to the emergency room right away.