Heartburn pills taken by millions of people can cause depression… and other common medications that can cause a bad mood

Millions of Britons could be at risk of medication-induced depression if they take heartburn pills and a range of other common routine medications.

Proton pump inhibitors (PPIs), a type of drug that helps reduce stomach acid, are one of the most commonly used drugs in Britain, with more than 74 million prescriptions in England alone by 2023.

But they are just one of many routine medications that can cause symptoms of depression in those who take them.

This is because PPIs, two examples of which are omeprazole and lansoprazole, can prevent the body from properly absorbing vitamin B12 – an essential nutrient found in meat, fish, dairy, eggs and some fortified grains that keeps the nervous system healthy.

A lack of this is a known cause of mental health problems which, according to the NHS, can range from ‘mild depression or anxiety to confusion and dementia’.

Package inserts that come with the drugs also acknowledge the risk and urge people to contact their doctor if they experience problems with their memory, confusion or depression while taking them.

A small study published in 2017 and based on about 350 older people found that about a sixth of cases of depression could be attributed to PPI use.

‘PPIs can block up to 80 percent of our stomach acid production,’ Deborah Grayson, pharmacist and expert in PPI medications, told MailOnline.

She added: ‘This means the amount of nutrition we can get from the food we have eaten has been reduced.

‘The body needs all our nutrients to produce the ‘happy hormone’ serotonin – and if we don’t absorb them from our food, the body can’t produce the hormone.

It is this lack of serotonin that can cause depression and low mood.

But PPIs aren’t the only commonly used drug linked to depression risk.

Some types of antibiotics, medications given to fight bacterial infections, have also been linked to low mood.

These links focus specifically on a class of antibiotics called fluoroquinolones, two notable drugs of which are levofloxacin and ciprofloxacin.

The risk of depression is recognized for both, with the NHS specifically stating that this can cause low mood in around one in 100 people prescribed ciprofloxacin.

Scientists have suggested that the drugs may alter the community of good bacteria in the gut, which could affect the production of mood-affecting hormones in the brain, theoretically increasing the risk of depression.

Antibiotics kill all bacteria, both the bad pathogens they are intended to target and, as collateral damage, the good pathogens in our gut.

This is why some patients are recommended to take probiotics, supplements that contain samples of good bacteria, to help boost their microbiome after a course of antibiotics.

Anticonvulsants are another class of medications linked to the risk of depression.

Drugs like topiramate and gabapentin, sold as Topamax and Neurontin respectively, are prescribed about 700,000 times a month and are known to cause depression or mood swings in about one in 100 people who take them.

Experts suspect the drugs may cause depression because of the way they suppress electrical activity in the brain and nerves to help treat conditions such as epilepsy.

Steroids, which are prescribed around 70,000 times a month in England to treat a range of conditions, are another routine drug linked to depression.

These medications, also called corticosteroids, are used to reduce inflammation in asthma, allergies and arthritis.

Experts suspect the drugs may affect the brain’s chemical response to stress and cause a range of psychiatric problems, including depression.

Some studies have estimated the risk of serious psychiatric problems from steroid medications at one in twenty, although significant differences are thought to exist depending on the dosage and the type of mental health problem encountered.

The NHS advice states that mental health problems linked to steroid tablets usually only occur if people take the medicines for more than three weeks.

Drugs related to depression can be difficult to diagnose due to the inherent complexity of the condition.

Doctors should consider whether a drug causes depression or whether a patient suffers from it due to some other unrelated reason related to their medication, such as problems in their personal life.

Ms Grayson urged people not to stop taking medicines if they experience a side effect such as depression, but to talk to their GP or pharmacist instead.

“A GP or pharmacist can intervene in some way, change it to a different medication, or check B12 and folic acid levels, both of which occur in depression, and find ways to compensate for what’s happening,” she said.

She added that it is important that people seek help for depression in all circumstances, even if it is related to their medication.

“Often patients look at the leaflet and notice that one of the side effects is depression and assume that because it says so in the leaflet they should just put up with it, which is clearly not the right thing to do,” she said.

If you feel depressed and these symptoms persist for more than two weeks, the NHS recommends talking to your GP about your symptoms.

It is especially important to do this if your symptoms do not improve, if it is affecting your work or relationships, and if you have been thinking about suicide or self-harm.