Is physical health linked to depression?

Siski Green / 03 August 2016

Find out what scientists know about the link between physical and emotional wellbeing.

Feelings of helplessness and hopelessness, persistent sadness and a lack of desire to see friends or do things you used to enjoy, are all symptoms of depression.

It’s easy to imagine that a person suffering with ongoing pain or who can’t function normally might start to feel depressed, but if you’re already depressed, can looking after your health help heal you? Here’s what the experts know.

Depression: alternatives to drug treatment

Depression can trigger risky lifestyle changes

An ex-smoker starts smoking again, someone who has always enjoyed the occasional drink begins to feel the need for alcohol to get through the day or perhaps the dark feelings of depression mean a person stops seeing friends, stops exercising or stops going outside at all.

All these behavioural changes are a result of the depression but will have a direct and detrimental effect on your health.

“There is a strong link between lifestyle changes and worsening depression,” says psychotherapist and faculty at The School of Life David Waters.

“It’s a vicious circle – you behave in ways that make you feel less worthwhile, smoking, drinking or not being sociable, and so the depression that triggered the behaviour becomes even more overpowering.”

Limiting the damage caused by bad habits

Why risky lifestyle changes make depressive symptoms worse

Research from Duke University Medical Centre, USA showed that nicotine, for example, helped relieve symptoms in non-smokers who had been diagnosed as depressed. And there’s plenty of evidence showing that depressed people are more likely to smoke.

Nicotine works, say researchers, by binding to certain receptors, activating them (and increasing depression symptoms) but then the receptors ‘turn off’ which leads to a reduction in depressive symptoms.

But the problem is that people don’t inhale nicotine alone, they also inhale a cocktail of health-destroying chemicals along with it. And health issues make you more likely to feel depressed (see below).

Add to that the fact that friends and family may criticise your habit or be disappointed in you, so your feeling of self-worth decrease, and you can see how smoking can make depression worse, not better. The good news is that researchers are working on similar substances, such as the drug mecamylamine and cytosine, which have the same effect.

Help for when you’re trying to give up smoking

Diseases likely to trigger depression

Parkinson’s disease, dementia, and multiple sclerosis are diseases where patients are quite likely to also show signs of depression.

Up to 60% of patients with Parkinson’s will experience mild or moderate depressive symptoms, according to the Parkinson’s Disease Foundation.

This isn’t simply about living with the psychological and emotional strains of the disease, research suggests it is a physically-led symptom.

This is because the feel-good chemical serotonin is produced in an area of the brain that can be affected by Parkinson’s.

Learn more about Parkinson’s disease

Similarly, dementia can also affect the brain in this way, as well as increasing risk of depression because of the psychological factors related to dwindling mental capacities.

Learn more about dementia

Multiple sclerosis is thought to damage signalling nerves and so affect mood, too, and can affect around 50% of patients.

Hypothyroidism is also linked to depression but thankfully the depression is a symptom of the illness that should be resolved once a diagnosis has been made and treatment started.

Health issues linked with depression

People who have been diagnosed with heart disease, have had a stroke or have high blood pressure are also more likely to have depression, but researchers can’t say for sure how or why they are linked.

What they do know is that these people with these diseases tend to report depression more than healthy people.

So, for example, according to the Mental Health Foundation, those with depression are 67% more likely to die from heart disease and a 50% greater likelihood of death from cancer.

This does not necessarily mean that being depressed makes your body more vulnerable to cancer, but may, for example, simply indicate that people with depression are more likely to smoke or drink heavily.

Or it could mean that people who are depressed are less able to seek medical help. If patients aren’t seeing their GP regularly they may miss out on tests that could be early indicators of cancer or heart disease – which caught early enough could prevent the onset of the disease.

Until more research is done, it’s impossible to know exactly how the two factors interact.

Physical inactivity is a major factor in depression

When you’re depressed exercise falls by the wayside. Similarly, if you’re ill and confined to a bed or can’t move as you usually would, you miss out on exercise too. That, in turn, can lead to depression.

Research shows that even just ten minutes of brisk walking can release feel-good chemicals called endorphins in your brain, so if you’ve been told to avoid exercise because of an illness, talk to your GP about ways you can exercise. Perhaps you can do stationary exercises or go swimming instead.

Why exercise is good for the brain

Being overweight as a result of physical inactivity could also worsen your depression in ways you might not imagine.

Researchers at the University of Northwestern Ohio put a group of people who had been previously diagnosed with depression on a diet that included aspartame, the artificial sweetener. Their symptoms worsened to such an extent that the study was called to a halt. This doesn’t mean that aspartame would cause depression in a non-depressed individual but it does suggest that it should be avoided by anyone diagnosed with depression.

How food can affect your mood

When you’re ill your diet changes. It might be that you no longer have the energy to prepare delicious fresh meals or that your appetite has changed or maybe you can’t even make it to the supermarket.

A study from Columbia University, USA, found that those people whose blood pressure rose more after eating carbs were also more likely to be diagnosed with depression later in life.

Good news: the same study revealed that eating more dietary fibre, whole grains, vegetables and non-juice fruit (ie whole fruit) was linked with a decreased risk.

Studies have also shown that the Mediterranean diet – high in healthy fats, fresh fruit and vegetables – is linked with lower levels of depression too, as well as lower risk of a host of health issues, such as heart disease, high blood pressure and diabetes.

10 healthy Mediterranean foods

 If you would like to talk to someone about your feelings of distress, despair or suicidal thoughts, call the Samaritans on 08457 90 90 90. 

The opinions expressed are those of the author and are not held by Saga unless specifically stated.

The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation.