8 health conditions that can be mistaken for depression but aren't

Feel exhausted and low? Health conditions that mimic depression are a real thing and you may need to help your GP or doctor understand the full picture when making an accurate diagnosis.

By Sabrina Rogers-Anderson

A few short decades ago, a diagnosis of depression was shrouded in shame.

But as the stigma surrounding mental health issues has slowly lifted and a growing number of people seek help, it’s estimated that 1 in 6 women and 1 in 8 men in Australia will experience depression in their lifetime.

While this shift in the social perception of mental health was much-needed, the pendulum may have swung too far in the opposite direction with research showing that 26% to 45% of patients referred for depression don’t meet the diagnostic criteria.

It turns out that a wide range of physical health conditions can cause symptoms that overlap those of depression.

Unless your GP is prepared to dig a little deeper and potentially do a physical examination, these health issues may be misdiagnosed as major depressive disorder. 

What are the symptoms of depression?

Depression affects how you think, feel and act. Symptoms can include:

• Feeling sad, teary, overwhelmed, irritable or angry
• Fatigue
• Appetite changes
• Trouble sleeping
• Difficulty focusing or making decisions
• Being less productive
• Loss of self-confidence
• Feelings of guilt, worthlessness or hopelessness
• Recurring negative thoughts
• Loss of interest in activities you used to enjoy
• Risky behaviours including alcohol and drugs
• Physical symptoms including headaches and upset stomach 
• Thoughts of suicide or death

Men often report feeling irritable, angry and tired while women are more likely to focus on their low mood.

Health conditions that masquerade as depression

Several mental health conditions and developmental disorders, including anxiety, bipolar disorder and ADHD, are commonly misdiagnosed as depression.

But what’s even more surprising is the large number of physical health conditions that can mimic major depressive disorder. Here are 8 to look out for.

Vitamin D or B12 deficiency

Despite living in a country with plenty of sunlight, which is our main source of vitamin D,  more than 1 in 3 Australians are vitamin D deficient.

A vitamin B12 deficiency is common in people who follow a vegetarian diet, but there are other causes as well.

Being low in either of these vitamins can lead to fatigue, weakness, difficulty thinking and mood changes, so it’s not surprising these conditions can be misdiagnosed as depression.

What your GP can do: A blood test to measure your vitamin and mineral levels.

Anaemia 

While only 4.5% of Australians are at risk of anaemia, the rates skyrocket after age 65 and hit 16% over the age of 75. 

People who are anaemic don’t have enough red blood cells, so their heart has to pump harder to deliver oxygen to their organs and muscles.

Anaemia can be caused by a deficiency in iron, vitamin B12 or folic acid, or less commonly by other health issues.

Like depression, anaemia can cause fatigue, weakness and brain fog. But it can also lead to dizziness, shortness of breath, frequent headaches and strange food cravings - none of which are symptoms of depression.

What your GP can do: Anaemia can be diagnosed with a blood test.

Medications

Several medications have been shown to cause depression in some people. These include:

• Anticonvulsants used to control epilepsy
• Beta-blockers and calcium-channel blockers used to treat high blood pressure and heart problems
• Barbiturates for anxiety or epileptic seizures
• Benzodiazepines for anxiety or insomnia
• Opioids for pain
• Statins to lower cholesterol and prevent heart problems
• Interferon alfa used to treat cancer

What your GP can do: They may want to switch you to another medication to treat your health issue or treat the depression with an antidepressant if the main medication is necessary for your condition. 

Hypothyroidism

The thyroid gland controls several of the body’s important functions, including body temperature, heart rate, blood pressure and weight.

An underactive thyroid (hypothyroidism) can cause fatigue, sadness and brain fog. It’s often misdiagnosed as depression and not treated appropriately.

Other symptoms of hypothyroidism that can help distinguish it from depression include weight gain, a puffy face, brittle hair and nails, a slow heart rate and an inability to tolerate the cold.

What your GP can do: Your doctor can examine your neck to see if your thyroid is enlarged, check your heart rate and order a blood test to measure your thyroid hormone levels.

Diabetes

Approximately 1 in 20 Australians have diabetes and the prevalence increases with age. By the ages of 80 to 84, almost 1 in 5 people live with the chronic disease.

Diabetes and depression share several symptoms, including being tired all the time, sleeping more than usual, having trouble concentrating and feeling low. 

Depression is also 2-3 times more likely in people with diabetes, making distinguishing the conditions even more complex.

If you experience excessive thirst or hunger or you’re passing a lot of urine, these may be clues that you have diabetes.

What your GP can do: If your doctor suspects diabetes, they’ll order a blood test to measure the amount of sugar in your blood when you’re fasting.

Dementia

When dementia first starts to appear, it can easily be confused with depression because the person may seem detached and not want to participate in conversations or regular activities.

But while depression can affect mental functioning and focus, dementia is characterised by short-term memory problems and confusion. People with dementia may also have issues with speaking, writing and motor skills.

What your GP can do: Diagnosing dementia involves a thorough medical history, physical examination and assessment of symptoms. Blood and urine tests, genetic testing and brain scans may also be required.

Cancer

Cancer and depression are intimately linked. Not only do 27% of cancer patients worldwide have depression, but studies have shown that a depression diagnosis often precedes the detection of cancer. 

This link is particularly strong with pancreatic cancer. A series of studies found that between 33% and 45% of pancreatic cancer patients reported mental health symptoms before physical ones. Researchers believe depression could be an early sign of cancer.

What your GP can do: Staying on top of your regular health checks can help detect cancer early. 

Parkinson’s disease

Parkinson’s disease (PD) is a neurodegenerative disorder that mainly affects neurons in the brain that produce mood-regulating chemicals including dopamine and serotonin. 

Depression is a feature of Parkinson’s because of these changes in brain chemistry and it may even appear before motor symptoms including slow movement and tremors, leading to a misdiagnosis.

What your GP can do: If your doctor suspects PD, they’ll analyse your medical history and symptoms and do a physical exam. Other tests such as an MRI or blood test may help confirm or rule out the diagnosis.

Helping your doctor get it right

It’s important to talk to your doctor about your physical symptoms as well as your emotional ones to help them correctly diagnose your condition.

Healthdirect’s Symptom Checker and Question Builder can help you prepare for your appointment without forgetting any important details or questions. 

Resources for people struggling

If you’re struggling or having thoughts of suicide, call 13 11 14 for 24/7 crisis support. If your life is in danger, call 000.

You may need support if you are worried about your own or someone else's mental health. This may be due to:

• changes to mood that worry you or others
• significant changes to personal hygiene or motivation
• difficulties concentrating
• getting confused about what is real and what is not
• behaviour like laughing or smiling at something others can't see or hear
• feelings of panic, like something bad is about to happen
• intense anxiety
• thoughts or actions of hurting yourself or ending your life
• thoughts of harming someone else.

Beyond Blue offer phone and chat support, as well as mental health checks you can do online.

Lifeline offer crisis chat and an SMS support service, as well as the phone support always available at 13 11 14

The information on this page is general information and should not be used to diagnose or treat a health problem or disease. Do not use the information found on this page as a substitute for professional health care advice. Any information you find on this page or on external sites which are linked to on this page should be verified with your professional health care provider.