Conditions That Look Like Depression But Aren't

Mental illness can be difficult to diagnose (via Annals of General Psychiatry). Unlike physical illnesses, such as diabetes and high blood pressure, there are no blood tests or medical instruments to pinpoint many psychiatric disorders. So, it's important to consult a practitioner who has the right knowledge and expertise.

Depression, in particular, is commonly misdiagnosed, according to a study from Johns Hopkins Bloomberg School of Public Health. The researchers looked at 5,639 patients in an outpatient setting who were given a diagnosis of depression by a doctor or other medical professional. They discovered that only 38.4 percent of subjects actually met the criteria for major depression when re-assessed using a semi-structured interview. Many of these people were already using psychiatric medications for their symptoms.

A common reason for a misdiagnosis is that many disorders share overlapping features (per Annals of General Psychiatry). This can make it hard for primary care physicians to tease them apart clinically. But an erroneous diagnosis can cause various problems, a major one being that people might be prescribed inappropriate medications. It also means that an individual misses out on timely and effective treatment, which can cause their symptoms to persist or worsen. Read on to find out which conditions often mimic depression.

Bipolar disorder is a complex and mysterious illness that's often misdiagnosed, according to research (via the Journal of the American Association of Nurse Practitioners). Around 60% of people with bipolar disorder are initially told that they have depression, and only 20% of patients are given the correct diagnosis in the first year of treatment. This means that some people are oblivious that they even have this serious, sometimes debilitating disorder.

Bipolar disorder and depression can look very similar at first glance, according to the Journal of the American Association of Nurse Practitioners. People with either condition tend to grapple with a depressive mood. This can be energy-sapping at times, and may impair various aspects of their lives. A major difference, however, is that bipolar disorder is marked by a combination of manic, hypomanic, and depressive episodes, whereas people with depression might not experience mania at all.

There are a number of reasons why bipolar disorder can be overlooked. It's easy to miss if the patient isn't exhibiting any severe symptoms, such as mania or rapid cycling, where they swing from a high to low mood. Research shows that people can live with the illness for years before receiving a diagnosis (per Acta Psychiatrica Scandinavica).

However, some of the antidepressants that are used to treat depression can exacerbate the symptoms of bipolar disorder (via the Journal of the American Association of Nurse Practitioners). This can lead to harmful outcomes, including antidepressant-induced mania and suicidality.

Attention deficit hyperactivity disorder (ADHD) is a commonly misdiagnosed mental illness (via Primary Psychiatry). It's often misidentified as depression, since ADHD symptoms can look a lot like depressive symptoms, Roberto Olivardia, a clinical associate and lecturer in psychology at Harvard Medical School, told CHADD. A key way to differentiate between the two disorders is to consider whether the loss of interest that a patient experiences is persistent or fleeting. For example, patients with ADHD may feel down when they're under-stimulated, but this tends to lift when they do something they enjoy. This is usually an indicator that they don't have clinical depression.

It's estimated that 18.6% of people have both ADHD and depression (via CHADD). When people feel overwhelmed by their inability to focus, remember things, and complete important tasks, they may spiral into an emotional rut (per ADDitude). Many people self-diagnose their difficulties as anxiety or depression.

A large number of people live with ADHD for years without receiving a diagnosis (via Primary Psychiatry). Many primary care physicians feel uncomfortable diagnosing ADHD due to a lack of thorough and straightforward screening tools. Around 44% of clinicians feel that there isn't a "clear diagnostic criteria." 

If left untreated, the symptoms of ADHD can worsen (via ADDitude). A lack of a diagnosis or a misdiagnosis can result in people being given the wrong information or medications. With the right kind of support, however, people with ADHD can lead healthy, productive, and fulfilling lives.

Endometriosis is a painful gynecological condition that affects up to 10% of women of reproductive age in the United States, per Johns Hopkins Medicine. The illness occurs when tissue that lines the uterus grows outside of it, such as in the ovaries or fallopian tubes.

Chronic pain associated with endometriosis can take a pretty heavy toll on a woman's mental health, note researchers (via International Journal of Environmental Research and Public Health). One of the most common symptoms of the condition is pelvic pain, which can lead to a reduced quality of life. It's not surprising then that healthcare professionals sometimes fail to identify endometriosis, and may attribute its symptoms to depression instead, per Refinery29.

A 2019 meta-analysis of studies found that depression is more prevalent among women with endometriosis than those without it (via American Journal of Obstetrics and Gynecology). Pain is often the number one cause of a plummeting mood. One study showed that women were just as likely to be depressed when they had pelvic pain without endometriosis as women who had both endometriosis and pelvic pain. For this reason, it can be helpful for clinicians to pin down and treat the root cause of these symptoms early.

Anemia is a blood disorder that's often caused by lack of iron (via StatPearls). People with the condition have low levels of red blood cells. As a result, their organs and tissues don't get enough oxygen. Some of the symptoms that people develop over time include tiredness, weakness, lethargy, and restless legs syndrome. Doctors sometimes blame these on a mental health issue such as depression, anxiety, or even burnout (per BMC Womens Health).

The misdiagnosis of iron deficiency anemia might seem unusual given its high frequency in non-pregnant women (via BMC Womens Health). This can have a number of dire consequences for moms-to-be, including unsuccessful treatment outcomes, poor disease management, delayed recovery, and a harsh impact on individuals' quality of life. People with anemia may develop a sense of helplessness the longer their condition remains invisible, which can lead to depression in the long-term.

An iron deficiency can also give rise to low mood and rob people of their energy and motivation (via Psychiatry and Clinical Neurosciences). Shortness of breath, chest pain, and unusual cravings are a few symptoms that may help differentiate between anemia and depression (via StatPearls). Your doctor can also use a blood test to check your complete blood count (CDC) before diagnosing you with anemia.

It's common for people with type 2 diabetes to have depression-like symptoms, per Diabetes UK. Often, they feel low, irritable, and tired. They may find themselves sleeping a lot or struggling to drift off, and sometimes having difficulty concentrating. In both type 1 and type 2 diabetes, people can feel overwhelmed about managing their condition, also termed "diabetes distress," which may be misdiagnosed as depression (via Endocrinology, Diabetes & Metabolism).

The relationship between diabetes and depression is complex (per The Journal of Medicine and Life). People with depression have a 60% greater likelihood of developing type 2 diabetes, while diabetes acts as a major risk factor for developing depression.

High blood sugar can lead to a low mood by bringing about various physiological and neurological changes in the body (via Geriatric Medicine Journal). By the same token, symptoms of depression, such as weight gain, off-kilter circadian rhythms, and feelings of helplessness, have been shown to make diabetes worse.

It's important for doctors to distinguish between these conditions early in order to minimize the vicious cycle between them, notes Diabetes UK. Depression can make it hard for people to manage their diabetes, such as taking their medication, testing their blood sugar levels, and exercising and eating in a helpful way. They may even avoid taking the necessary steps to seek treatment.

Low mood, being tired, and general aches are just some of the features of low vitamin D (via Patient). A vitamin D deficiency occurs when your body doesn't get enough vitamin D from the sun or food. People may not have any symptoms right away, and its effects can sometimes be subtle.

In some people, low levels of vitamin D can mirror a mood disorder (per Mayo Clinic Proceedings). People may also become more susceptible to muscle pain and weakness. And so, it's no surprise that those with a vitamin D deficiency are sometimes mistakenly identified as struggling with depression.

Research shows that many patients diagnosed with depression have plummeting levels of vitamin D in their blood (via Current Drug Targets). There's also evidence that insufficient vitamin D elevates an individual's risk of depression, according to Scientific Reports. Therefore, clinicians should test at-risk people for low levels of vitamin D, say researchers (per Mayo Clinic Proceedings). This could help them treat a potential nutrient deficiency before it leads to other physical or mental health issues.