Mother-of-two Marie Ramain had experimented unsuccessfully with several forms of therapy and medication since being diagnosed with depression 20 years ago.
"I've met seven different experts in France and have gone through several different kinds of therapies," Marie, now living in Dublin, says.
"The advice I got was always intellectual: take part in a sport or a hobby. I've done yoga, I've tried a few activities. But the sense of sheer exhaustion that I've been feeling since I was in high school never disappeared."
When the family relocated to Dublin last July with her husband's job, Marie (36) was referred to Stillorgan GP Edmond O'Flaherty. Another doctor had known of Edmond's interest in nutrient therapy, treatments he and a growing number of doctors internationally believe to be complementary to traditional medical remedies.
Dr O'Flaherty ordered a blood test for Marie and when the results came back a few weeks later she was surprised that he proposed a simple injection of vitamin B12 as her treatment.
"He said, 'You have too much copper, it's as simple as that. When you have too much copper in your body, you have depression,'" Marie recalls.
"As soon as I had this injection, I felt energy again, it was like a big weight flying away."
Dr O'Flaherty put Marie on a course of nutrient therapy combining vitamin C, vitamin B6, B12, manganese, zinc and fish oils. Six months later, she has never felt better.
"I haven't felt this full of energy since I was a child," Marie says. "In the past I would feel like going back to bed and sleeping again for two or three hours.
"For many years, I've felt really handicapped but now when I wake up in the morning, I feel that I have slept enough and look forward to the beginning of the day."
She also feels that visiting the health shop instead of the pharmacy to buy her treatments is "good for your morale".
"You are in the queue with people who are just buying rice or carrot juice, you don't feel like you're in a place for sick people, you feel like you are in a place for healthy people," she laughs.
But while nutrient therapy may be attracting a growing number of fans, it also has its sceptics.
Many psychiatrists feel it offers an oversimplified approach towards treating complex mental health conditions.
Most of us have a vague understanding of the beneficial effects of vitamins and minerals but the supplements in our local health food shop could lay claim to a greater benefit than we realise -- the power to treat mental illnesses such as post-natal depression, ADHD and childhood autism.
The growing use of nutrient therapy is offering hope to people suffering from mental health illnesses, empowering patients to manage their own conditions by using a combination of vitamins, minerals and amino acids to treat chemical imbalances in the brain.
And while it's a relatively new concept in Ireland, in the US numerous studies have shown how nutrient therapy has enabled thousands of patients to come off medication altogether or to dramatically reduce the amount of medication they are on.
The concept originated in Canada in the 1960s. But it's the research of chemical engineer Dr Bill Walsh that has transformed the idea into a reality.
While working with inmates at a Chicago prison in 1972, Dr Walsh analysed blood, urine and tissue from 100 volunteers. He discovered that the majority of prisoners' samples were low in copper, zinc and manganese, while their blood histamine levels were high.
His findings raised two exciting possibilities: firstly that the impulse to commit violent crime could result from a biochemical imbalance and secondly, that nutrient therapy, rather than medication, could offer effective treatment to the prisoners. In 1982, he joined forces with biochemist Dr Carl Pfeiffer, a pioneer in the therapeutic use of amino acids in treating schizophrenia and bi-polar disorder.
Together they set up the Health Research Institute in Illinois, and later the Pfeiffer Treatment Center, which has become the world's largest nutritional clinic for treating biochemical disorders since its establishment in 1989.
In 85pc of ADHD and autism patients, nutrient therapy has eliminated or reduced their symptoms, while 80pc of patients with depression and 75pc of patients with schizophrenia have recovered or improved.
"I get a lot of phone calls from doctors who might say, 'I've got this patient who I've been working with for a few years. They went to your clinic and now they're better. Can you please tell me what you did?'" Bill says.
"The weapons we use are nutrients, vitamins and minerals. At that point, half lose interest, and some of them will say, 'how could that possibly work -- don't you need a powerful drug for a serious condition like schizophrenia or autism?'
"I'll answer by asking the question -- where do our neurotransmitters come from? Where do we get serotonin, dopamine? Really, they come from nutrients. We're not born with our supply of our neurotransmitters, they're basically created every day.
"The scientists have now worked out, step-by-step, how these individual neurotransmitters are formed and how nutrients are involved. Most people have some abnormalities in nutrient levels. And if it happens to be one of those nutrients that is critically important in forming, say, serotonin, you can expect that there will be a problem with your mental health."
In 2008, Bill set up the Walsh Research Institute, which has published studies showing links between post-natal depression and elevated copper levels in peer-reviewed journals in the US.
In addition, a nutrient therapy training programme he established in Australia in 1998 is now accredited by the Royal Australian College of General Practitioners and has been replicated in Norway.
Interest in nutrient therapy is also growing amongst Irish doctors. Last July, 200 people turned up to hear Bill speak on the subject at a conference in Dublin. He hopes to return later this year to establish a training programme that would educate up to 20 doctors, and to eventually make Dublin the base for the first nutrient therapy clinic in Europe.
Dr Edmond O'Flaherty is one of a handful of Irish doctors among the 70 physicians worldwide who have trained under Walsh's nutrient therapy programme.
An article in the eminent journal 'Archives of General Psychiatry' about the benefits of fish oil in treating mental health disorders first piqued his interest and, in 2006, he travelled to Australia for the seven-day training course, where he witnessed first hand how effective nutrient therapies were in treating autism.
"It's a very hard condition to treat, but I saw some very good results in Australia," Dr O'Flaherty recalls. "I actually met the kids who had grown out of the autism and were perfectly normal. I couldn't believe my eyes."
As a pioneer of nutrient therapy in Ireland, Edmond is cautious about using it as a replacement for traditional medication.
However, he has found that complementing his patients' traditional therapies with tailored combinations of nutrients has helped them reduce their medication for conditions ranging from depression to anorexia nervosa and, in one case, severe paranoid schizophrenia.
"Paranoid schizophrenics often have high copper in their blood," he explains. "There's a chemical in the brain called dopamine that's converted into a chemical called noradrenalin. If you have high copper in your blood, then you finish up with lots of noradrenalin.
"If you have lots of noradrenalin, some of it leads to the production of adrenaline, which is a horrible chemical that makes you 'fight or flight', as it were. It makes you feel anxious and agitated."
Edmond 'prescribed' zinc and a combination of other nutrients for the patient and watched as his condition went from "dire to great over a period of three months after 30 years on medication".
"I would see it as complementary rather than alternative," he says. "People with serious mental illness like bi-polar or schizophrenia, only a psychiatrist can take them off medication and I wouldn't dream of arguing with that. But with depression, sometimes nutrients are enough after a few months.
Dr Niall Crumlish, a consultant psychiatrist at St James's Hospital, Dublin, is one of those who believes more evidence is needed to qualify nutrient therapy as a medical treatment.
"The idea that what's important in terms of whether people offend or not is their levels of copper and zinc, doesn't make a whole lot of intuitive sense because there is obviously so much more going on. You're dismissing an entire field of sociology," says Dr Crumlish.
"The whole issue of nutrition is really, really important and I think it's one thing we do have to be conscious about. When I see people I'm constantly checking things like vitamin B levels and various other nutritional indicators, because there tends to be an association between poor nutrition and mental health.
"It's a bi-directional thing but it's more likely that people with mental health problems don't eat properly, rather than that the poor nutrition causes mental health problems."
Dr O'Flaherty believes psychiatrists are reluctant to embrace the benefits of nutrient therapy because they fear its implications.
"There are no drug companies involved; there is no money involved. People can buy the drugs in a chemist or a health food shop. Psychiatrists don't like that because their living depends on these people taking medications," he says.
The economic benefits of nutrient therapy are potentially significant, given that the HSE spent almost €300m on drugs for treating mental health and behavioural disorders in 2008 and 2009.
However, Dr Crumlish argues that the only fear psychiatrists have about nutrient therapy is the lack of research behind it. In his view, doctors need to make their patients aware of this when discussing the treatment with them.
"The idea of it being complementary is fine, but I would say talk to your GP," he says. "I would be very cautious about any treatment that is unproven. The potential adverse effects haven't been studied -- we don't know a lot about that until more trials are done."
Marie, however, needs no convincing of the power nutrient therapy holds. She believes it has succeeded where 20 years of conventional therapies failed and has given her a renewed energy to keep up with the demands of her seven-year-old daughter and five-year-old son.
"My message is, have a good blood test first before telling your life story to any psychiatrist," she says.
Dr Bill Walsh is currently writing a book about nutrient therapy, which is due to be published later this year
For more information about nutrient therapy, visit the Pfeiffer Treatment Centre at: http://www.hriptc.org