New and very different schizophrenia drug shows promise

Sep 3 2007

Scientists at Eli Lilly say the first human trial of a new schizophrenia drug shows promise for sufferers of the debilitating mental illness.

There are already many drugs which are designed to treat schizophrenia but this latest drug differs in that unlike all other antipsychotics it targets the glutamate receptors in the brain rather than dopamine.

The scientists say patients treated with the new drug "LY2140023" showed improvements in symptoms and suffered fewer side effects.

Schizophrenia affects around 1% of the population and is a chronic mental illness. The main symptoms are hallucinations (hearing voices), delusions (a firm belief in something that isn't true) and changes in outlook and personality.

Schizophrenia can manifest itself in positive symptoms (hallucinations, delusions and thought disorder), and in negative symptoms such as social withdrawal, apathy and emotional blunting with symptoms such as psychomotor retardation, lack of insight, poor attention and impulse control.

The antipsychotic drugs currently used to alleviate these symptoms can have serious side effects such a violent tremor, similar to that experienced by Parkinson's disease sufferers; for some, the side effects are so distressing that they often stop taking the medication and run the risk of a major relapse.

For decades changes in glutamate neurotransmission has been linked to schizophrenia, but all commonly prescribed antipsychotics act on the dopamine receptors.

Dr. Sandeep Patil and colleagues suspected that a drug directly targeting the chemical glutamate and its NMDA receptor could be a possible alternative.

Earlier work in rats by Dr. Patil's team showed drugs such LY2140023, which act on these signals appeared to work as antipsychotics so they conducted a trial with 97 patients along with smaller groups who were given placebos or olanzipine, a commonly prescribed anti-psychotic medication.

Over the course of four weeks, it was found that patients receiving the experimental drug fared as well as those taking conventional olanzapine.

According to the World Health Organisation schizophrenia affects approximately 1 in 250 people, emerging in men in their late teens and early 20s, and a decade later in women; there is no known cure for the chronic disease.

The researchers do say however that the study was very much a preliminary one and say more trials to test LY2140023 against other drugs and over long time periods are now needed.

Experts say the results are promising and should prompt further trials which could lead to the development of a third generation of drug treatments for schizophrenia.

The study is published in the journal Nature Science.