When his OCD was at its worst, two years ago, David Bass developed an irrational terror of being sent to prison. He was stalked by the fear that he was going to knock someone over in his car, and driving became such an ordeal for him that he only got behind the wheel when he couldn't avoid it. Gradually, he began losing touch with reality: once, he became convinced that he had raped someone when, in fact, he had just looked at them. He waited in bed, terrified, for the police to collect him.

Most people understand OCD as having an extra-tidy house, washing your hands a lot, or endlessly checking that you locked the door. But for some, the reality of the anxiety disorder is obsessions, compulsions and the kind of fears that Bass describes, which often come to dominate the lives of sufferers.

Bass, a TV presenter, is all too familiar with the devastating effects of this type of mental illness. "OCD takes over your life," he says. "It's like a bully. It feels like it's waiting for you, like it's got a mind of its own, affecting whatever is most important to you at the time.

"Not long after that, I was recording for a show called ITV at the Movies and my obsession with sweating started. Whenever I was on camera, I was worried that I was sweating and that made me more anxious. I was also afraid to go to sleep and it became a vicious circle. Sometimes I would only get two or three hours of sleep before a show. It wasn't a great situation to be in: interviewing celebrities, having had no sleep and constantly worrying about whether I was sweating."

About two years ago, Bass's OCD became so bad that he started living as a virtual recluse. "I was desperate for any lifeline." It was then that a friend told him about a gadget whose makers claimed it could help sufferers cope with OCD. He was sceptical at first, but as someone who had suffered from OCD since he was a child, he was willing to try anything.

The Alpha-Stim (alpha-stim.co.uk) is a small device with clips that attach to the earlobes, and it works by provoking a reaction in the electrical and chemical synapses in the body using electric currents. This is described as "cranial electrotherapy stimualation" and the idea is that it increases alpha brain waves.

Bass immediately set about using the device, which costs from £449, several times each day. "It helped immediately but the effect was cumulative, too. It stopped my mind racing, and brought me down to a relaxed state. I suppose it's a bit like that feeling when you've had your first pint in the pub. But with this, I don't need alcohol or drugs to medicate myself. I know a lot of people with mental-health problems turn to them, but it's not the way I want to go."

Dr Lesley Parkinson, a clinical psychologist specialising in neuropsycho-physiology who is a spokesperson for Alpha-Stim, explains how the device can help an anxiety disorder as severe as OCD: "The repetitive compulsive behaviours and cognitions of OCD are initially aimed at reducing anxiety – these can include excess washing, cleaning and checking rituals. The behaviour and thoughts are recognised by the individual as being irrational, so in other words, they have insight. What the Alpha-Stim can do is regulate imbalances within the central nervous-system function – this leads to a reduction in anxiety levels and a calming of neuronal activity, so that the intrusive thoughts and urges for compulsive behaviours are reduced."

The usual treatments for OCD are initially behavioural therapy, which could involve CBT (Cognitive Behavioural Therapy) that will include graded exposure and response prevention (ERP). A patient may need medication if the CBT fails to treat mild OCD, or if the sufferer has moderate or severe OCD. Selective serotonin reuptake inhibitors (SSRIs) are usually prescribed. "The Alpha-Stim is particularly beneficial for those who are non-medication responders," she says. "It can also reduce anxiety levels so that the individual is more able to be co-operative with other forms of intervention such as CBT."

The Alpha-Stim isn't just for OCD – it's designed for anxiety, depression, insomnia, pain, fibromyalgia and addictions. The journalist Patrick Strudwick suffered from severe anxiety and used it four years ago when it came out in the UK. It had already been widely used around the world for more than 20 years, but it's only recently that it's been marketed in the UK for private use. Strudwick liked it initially and found it gave him temporary relief. But for him, anxiety was something that he wanted to be able to manage himself. "The act of using something – a device – served to remind me that there was something wrong," he says. "To get better, I felt I needed to understand how my anxiety operated – and how I was fuelling it.

"I can see it working as a first step – a tool. But to me, anxiety is complex, and your approach needs to be the same. So this wasn't enough. Thankfully, anxiety is not a feature of my life any more in the same way that it was, and that's not down to one thing, it's because of breathing, meditation, exercise, sleep, nutrition, environmental factors... It's a very individual thing, though. For me, the Alpha-Stim was helpful for a while – for some I know it's a godsend. I just needed a more multipronged approach."

But Bass is now at a point where his OCD is more manageable thanks to the device. "I just use it once or twice a day now, and at bedtime if I'm having trouble sleeping. I'm slowly improving." Dr Jeremy Broadhead, a consultant psychiatrist at Sevenoaks Medical Centre (sevenoaksmedicalcentre.com), says that CBT is the treatment for which there is best research evidence, and there is strong research evidence for certain medications, too. But, he adds, the brain is too complicated an organ for the same things to work for everyone. "The self-treatment microcurrent therapy has worked for David, and that's wonderful. It demonstrates how important it is to keep on searching for your own solution, once first-line treatments have not helped."

Although the Alpha-Stim has helped Bass, his problems aren't solved. He's still on medication and some days are good, some days a new obsessive thought creeps in. Some days he can even feel suicidal. "There's a stigma attached to OCD which doesn't help," he says. "When people find out that I have the condition, I get comments like, 'Oh good, you can come over and clean my house'. People with mental illness are fair game. The strange thing is that I wouldn't be without my OCD. I just need to be able to manage it. It's part of who I am and without it, I wouldn't have the mind that I do, I wouldn't be me. And in spite of everything, I'm proud to be that person."

OCD: The Facts

* Between 2 and 3 per cent of the population between the ages of 18 and 54 suffer from OCD, which makes it more common than mental disorders such as schizophrenia, bipolar disorder or panic disorder.

* OCD is a disorder of the brain and results in behaviour that causes severe anxieties in those affected, including obsessions and compulsions.

* The World Health Organisation (WHO) ranked OCD in the top 10 most disabling illnesses of any kind, in terms of lost earnings and diminished quality of life.

* Sufferers frequently experience intrusive and unwelcome obsessional thoughts but are unlikely to go through with any of the urges.

* Up 60 per cent of sufferers will have no overt compulsions.