Spot of bother for anti-acne drug

16 November 2007

A powerful spot-clearing drug has been bringing smiles to people with severe acne for 25 years. But new research shows it also messes with brain chemicals that can trigger depression.

Could fighting spots bring on the blues? Antenna finds out more...

Most people get occasional spots, but severe acne often won't respond to conventional treatment.

Image: iStockphoto/Graca Victoria

Eight out of ten teenagers get acne to some degree, but for an unlucky few the severe spots won't shift. That's why 6000 people in the UK are prescribed the powerful drug isotretinoin every year. But some parents and doctors are concerned by high rates of depression and suicide in patients.
Now, researchers have added weight to these worries by discovering a chemical pathway that links the drug with depression. In a paper published in the journal Experimental Biology and Medicine, scientists show that the drug interferes with mood-related chemicals in brain cells from rats.

In the UK, 26 people have committed suicide while taking the drug.

Image: iStockphoto/Amanda Rohde

What did the scientists do?
The researchers took cells from rats' brains, and added the acne drug to see what would happen. They noticed that the cells changed the way they processed serotonin, a brain chemical associated with maintaining a happy mood.

Scientists looked at brain cells that produced the mood-altering chemical serotonin.

Image: iStockphoto/Ben Greer

Sarah Bailey, who led the research at the University of Bath, explains what happened: 'We know that serotonin acts as a messenger between cells in the brain and controls mood.
'But when we added the acne drug, the cells started to produce more of a protein that sucks up serotonin and locks it away inside cells. This means less of the serotonin is free to travel around the brain and act.'

Sarah Bailey researches drug interactions at the University of Bath.

Image: University of Bath

But how is this linked to depression?
Sarah says: 'People with unusually low levels of serotonin are more likely to be depressed. In fact, we know that we can help treat depression by blocking exactly the same proteins that the acne drug appeared to increase.'

Drugs such as Prozac combat depression by increasing active serotonin levels - the opposite of what was seen with the acne drug.

What happens now?
'It's still early days,' says Sarah. 'These tests were done on cells from rats' brains. We've a lot of work to do before we can say whether the same changes actually happen in human brains. We'll start by looking in animals.'

Earlier studies have shown that mice on the acne drug get depressed, but this is the first evidence of a chemical pathway that could be the cause.

But what's the advice to patients already on the anti-acne pills?
Doctors already know that the acne drug is powerful; pregnant women aren't allowed to take it, and patients starting on the medicine are warned that it might cause side effects including depression.
Nina Goad from the British Association of Dermatologists says: 'As with any drug for any disease, the dermatologist prescribing the medicine should always discuss the impact of acne, and the benefits and side effects of treatment with the patient.'

Doctors aren't allowed to prescribe isotretinoin during pregnancy as the powerful drug affects the brains of developing fetuses.

Image: Patrick Talbert

And patients say it's still worth the risk. Kevin McIver suffered from severe acne until he took a three-month course of the drug in 2003.
'I was warned that the drug might cause depression, but having such bad skin was already making me feel very low. I felt tired when taking the drug, but my skin has been fine since, so in my case it was definitely a good choice,' says Kevin.

Kevin's acne didn't respond to standard medicines for four years before he took isotretinoin.

Image: Kevin McIver

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