Unlike current anti-psychotic drugs, which block the uptake of anaturally occurring chemical called dopamine, the new drug acts on a different neurotransmitter, glutamate.
The new treatment also reduced certain undesirable side-effects, according to the study, published in the British journal Nature Science.Imbalances in the brain of these chemicals are largely responsible for schizophrenia's disabling symptoms, which range from hallucinations and delusions to a severely impaired ability to express emotion.
Environmental factors are thought to play a role too.
Sufferers often hear voices and may believe that other people are reading their minds or controlling their thoughts. These frightening experiences can cause withdrawal and extreme agitation.
No known cure
There is no known cure for the chronic disease, which affects
approximately 1 in 250 people, emerging in men in their late teens and
early 20s, and a decade later in women, according to the World Health
Organisation.
Until now, the only drugs able to keep the most severe symptoms in check without debilitating side-effects acted on dopamine receptors.
Dopamine is the chemical messenger in the brain mainly involved with thinking, emotions, behaviour and perception.
In a double blind clinical trial, a team led by Sandeep Patil, a researcher at Eli Lilly, which funded the study, administered the new drug - known as LY2140023 - to 97 patients alongside smaller groups given placebos or olanzipine, a commonly prescribed anti-psychotic medication.
LY2140023 matched the effectiveness of olanzipine for both "positive" symptoms such as hallucinations as well as "negative" ones, including withdrawal.
Avoided adverse effects
As important, it avoided some of the adverse effects associated with
dopamine-targeting drugs: weight gain, increases in blood fats called
triglycerides, periodontitis and inflammation of the gums.
Scientists have suspected for decades that improper neurotransmission of glutamate was linked to schizophrenia, but up to now the precise mechanism was not understood.
The researchers cautioned that this was only a "proof-of-concept" study to see whether the drug held promise in the treatment of schizophrenia, and that more trials to test LY2140023 against other drugs and over long time periods were needed. – (Sapa-AFP)
Read more:
What is Schizophrenia?
Schizophrenia: A mother’s tale
September 2007