Why it never hurts to get a blood test before diagnosis.
-Ralph Ryback, MD
“It ain’t what you don’t know that gets you into trouble. It is what you know for sure that just ain’t so.”
This quote, frequently attributed to Mark Twain, describes the dangers of believing something false with all your heart. Instead of focusing on treating the real problem, you find yourself putting all of your effort into fixing another issue that bears little relevance to your future. This quote was most famously used in the film “An Inconvenient Truth” to highlight the risks associated with denying climate change.
The quote is also — quite ironically — misattributed. At the very least, it was uttered by someone other than Mark Twain.
Nevertheless, the wisdom behind it is hard to ignore. When you believe in something that is false, you can suffer adverse effects. This is particularly true if your false belief involves your health.
Depression: A common misdiagnosis
Mental illness is always a little difficult to diagnose, particularly because there are no physiological tests to help clinicians out. Diabetes is diagnosed through blood tests, cancer is diagnosed through biopsies and medical imaging … and mental illness is diagnosed through checklists of self-reported symptoms.
For this reason, mental illnesses including depression are sometimes misdiagnosed. According to a 2012 article in Current Psychiatry, 26 to 45 percent of patients referred for “depression” did not meet diagnostic criteria for a depressive illness. A 2009 meta-analysis discovered that general practitioners can only correctly identify depression in patients in 47.3 percent of cases and that many doctors diagnose depression in people who don’t have it.
Here are four conditions that are commonly mistaken for depression, both by clinicians and the public.
1. Bipolar disorder
Bipolar disorder, like depression, involves periods of intense lows. During these lows, people with bipolar disorder experience the exact same symptoms found in depression. They may feel hopeless, worthless or even suicidal. Unlike depression, people with bipolar disorder also experience high periods, or mania, where they feel confident, productive and otherwise on top of the world. Sometimes, this manic phase is so pleasant that people with the disorder are unable to recognize it as part of their illness. Instead, they only seek help during the low periods.
According to a study published in The British Journal of Psychiatry, up to 22 percent of people with bipolar disorder are mistakenly diagnosed with depression. Another study found that people with bipolar disorder have an average gap of 10 years before they receive the proper diagnosis. Recognizing the difference between bipolar disorder and depression is vital, since the medications used to treat depression can often worsen the symptoms of bipolar.
Hypothyroidism is a condition in which the thyroid gland does not release a sufficient amount of hormones. Because these hormones are necessary for the brain and body to function, people with this disorder typically experience fatigue, diminished concentration and a low mood — all characteristics of depression.
Researchers estimate that 20 million Americans have a form of thyroid disease, but that up to 60 percent of these people are unaware of their condition. Instead, they erroneously believe that they are easily fatigued, lazy or — yes — depressed.
Unlike depression, people with hypothyroidism are overly sensitive to cold temperatures and may feel cold all the time. They’re also more likely to experience dry skin, hair loss and a hoarse voice. Thankfully, hypothyroidism can be checked with a simple blood test, and treating hypothyroidism requires only one pill a day.
Diabetes is another illness that is commonly confused with depression. Often, people develop Type 2 diabetes without recognizing it. They may suddenly find themselves losing weight, feeling fatigued and growing more irritable than usual. Since all of these symptoms are also associated with depression, they may fail to recognize that their body is having problems with insulin. Insulin resistance, one of the precursors to Type 2 diabetes, has been significantly linked to depression.
People with diabetes are also at risk for “diabetes distress,” a condition that mimics depression. A study conducted in 2014 found that people who were diagnosed with both diabetes and depression experienced reduced depression symptoms after receiving interventions designed to help manage diabetes. In other words, their symptoms were not due to depression, but instead due to the stress of living with a chronic illness.
“Because depression is measured with scales that are symptom-based and not tied to cause, in many cases these symptoms may actually reflect the distress that people are having about their diabetes, and not a clinical diagnosis of depression,” said lead author of the study, Lawrence Fisher, Ph.D., ABPP.
4. Chronic fatigue syndrome
Chronic fatigue syndrome — also known as myalgic encephalomyelitis or systemic exertion intolerance disease — is an illness characterized by extreme fatigue with no apparent cause. Chronic fatigue syndrome also involves difficulties concentrating, muscle pain and problems with sleep. Since these symptoms are also associated with depression, people with chronic fatigue syndrome are frequently misdiagnosed. A study published in The Primary Care Companion to the Journal of Clinical Psychiatry found that chronic fatigue syndrome is under-diagnosed in more than 80 percent of the people who have it and that depression is the most common misdiagnosis.
Thankfully, there is at least one clear difference between depression and chronic fatigue syndrome. Whereas people with depression are both exhausted and uninterested in their hobbies, people with chronic fatigue syndrome may still want to participate in their hobbies despite lacking the energy.
Does anyone have depression?
Yes! Depression is a very real, very serious illness that affects millions of people each year. The majority of people who are diagnosed with depression are diagnosed correctly and are able to recover with proper therapy and medication.
Still, a misdiagnosis is always possible. If you are being treated for depression and aren’t experiencing any benefits, it is entirely possible that you have a disorder that is mimicking the condition. Before starting an antidepressant regimen, it never hurts to take a blood test to rule out one of the commonly confused conditions such as hypothyroidism or diabetes.
Remember: “It ain’t what you don’t know that gets you into trouble. It is what you know for sure that just ain’t so.”