Is the only drug for restless leg syndrome to blame for patients' suicidal thoughts?

The main treatment for people suffering from agonising restless leg syndrome could make the symptoms permanently worse, campaigners are warning.

The condition, which affects up to 10 per cent of the population and is more common in women, causes an unpleasant 'crawling' sensation in the legs, mostly at night, and an almost irresistible urge to move.

In those worst affected, it can interrupt sleep, damage mental health, ruin relationships and careers. But drugs called dopamine agonists commonly prescribed by doctors to ease the symptoms may actually exacerbate problems in up to half of patients, studies have found. In some cases the effects can't be reversed.

Describing the situation as 'an appalling medical scandal', the charity RLS-UK says many people have been left with unbearable symptoms, even after upping their dose of the drugs to the maximum level to end their suffering.

Others develop bizarre addictive behaviours such as gambling or compulsive shopping, it says.

In one shocking example, Joeli Brearley, 45, became suicidal after being forced to repeatedly increase her dose of a dopamine agonist called ropinirole – which worsened her symptoms so that she was unable to sleep for days.

Ms Brearley, a mother-of-two from York, who launched the campaign group Pregnant Then Screwed which campaigns for mother's rights in the workplace, first sought help from her GP three years ago after her restless leg symptoms became severe following two pregnancies.

'Initially it was a miracle cure,' she says. 'Before, I was having to jog on the spot watching TV in the evenings, and was regularly up pacing around or doing squats in the middle of the night as this crawling feeling in my legs kept me awake. After taking ropinirole the symptoms vanished and I started sleeping like a baby. It was amazing. But they started slowly creeping back, and the GP kept advising me to increase the dose.

'Eventually I was on the maximum dose and it was as if I wasn't taking them at all. It was awful – I wasn't sleeping, and I was desperate. I was a mess.' So she decided to go 'cold turkey' to come off the drugs – but her symptoms escalated rapidly. It felt like her knees 'were being stabbed repeatedly' and she was up every few minutes to pace the floor. She was getting so little sleep that she began hallucinating and having intrusive thoughts.

'It was torture,' she recalls. 'My partner kept finding me on the floor, sobbing. I was getting knives out of the drawers and thinking about stabbing my legs. I'd think about taking an overdose just so it would be over. I was so close to doing something harmful. But when I called the GP to say I didn't think I could survive it, they told me to go back on the drugs.'

While the cause of restless leg syndrome is unclear, it is thought to be linked to a malfunction in how a chemical called dopamine, which helps control muscle movement, is transported in the brain.

Low levels of iron, which has a role in creating dopamine, may be a factor, which is why one in four women develop RLS during pregnancy. In fact, people with RLS might need higher levels of iron in the body than others, experts say.

Dopamine agonists work by 'tricking' the brain into thinking it is getting the dopamine it needs. They are also prescribed to control symptoms of Parkinson's disease.

According to a survey by RLS-UK of over 3,000 people with RLS, 65 per cent who had taken dopamine agonists have switched medications because symptoms worsened. That worsening is known as 'augmentation'.

Dr Julian Spinks, a GP in Kent and a trustee of RLS-UK, says: 'Dopamine agonists are absolutely brilliant at treating the condition initially. But they seem to be particularly associated with augmentation. Most clinicians don't understand that by increasing the dose they are feeding this process.

'Tackling it often means coming off the drug, which means some degree of withdrawal and much worse RLS symptoms.'

The American Academy of Sleep Medicine is set to update its guidelines to no longer recommend dopamine agonists for RLS.

Other treatments for RLS include epilepsy drugs gabapentin and pregabalin. But these often don't work if given after dopamine agonists, the charity says.

Ms Brearley, who is taking codeine to manage her symptoms, paid £600 for an iron infusion at a private clinic earlier this month, although it is too soon to say what difference it has made.

Julie Gould, from RLS-UK, said: 'We want GPs to be better trained to understand RLS and the problems associated with dopamine agonists and for much more research into this condition.'