 |
|
HOPE FOR GENETIC TESTS TO TREAT SCHIZOPHRENIA AND ASTHMA
January 04, 2000Scientists are moving a step closer to providing treatment based on a person's genetic
profile. Doctors at the Institute of Psychiatry, Kings College, London have found a
way to predict the response of an antipsychotic drug called clozapine used for the
treatment of schizophrenia.
At the Millennium meeting of the British Pharmacological Society held at the
University of Cambridge (4-7 January), Professor Robert Kerwin and Dr Maria Arranz
in the department of psychological medicine announced recent genetic studies that
helped them to identify the patients who would be most likely to benefit from
treatment with clozapine. Clozapine is one of a number of antipsychotic drugs
available. It is a potent and expensive drug although it is not effective for all the
patients.
Professor Kerwin and Dr Arranz looked at 19 genetic variations in the receptor, the
drug's binding site on brain cells, and the biological transport mechanisms responsible
for the action of clozapine. Two hundred patients who suffer from schizophrenia were
involved in the study and were treated with clozapine for at least three months. "The
results of the genetic analysis show for the first time that it is possible to predict in
80% of cases those patients who will respond well to clozapine. This may lead to a
simple new test to select patients most suited to this drug," said Professor Kerwin.
The study of genetic factors that influence a person's response to drug treatment -
pharamacogenetics - is now progressing rapidly. Pharmacogenetics is the focus for a
keynote lecture (6 January) being given by Professor Kerwin, and a one-day
symposium (7 January).
"One of the main aims of pharmacogenetics is predictability testing," said Professor
Kerwin. "This offers the potential to personalise therapy. Our results show how we
could, in the future, individualise psychiatric treatment in a group of people who
respond in different ways to different drugs."
The genetic basis for adverse reactions to antipsychotic drug treatment is of intense
interest to Dr Vincenzo Basile from the centre for addiction and mental health
(CAMH) at the University of Toronto in Canada, who also gave a lecture at the BPS
meeting. Dr Basile has conducted research into tardive dyskinesia (TD), a condition
that occurs in 20% - 30% of patients as a result of their treatment. In TD, a patient's
muscles, particularly those of the face and tongue, move involuntarily and abnormally,
and this distressing effect is often irreversible.
In early studies of dopamine receptors (the binding site for a chemical messenger in the
brain involved in movement) Dr Basile found that there could be a genetic association
between the action of these receptors related to drug treatment, and the development
of TD.
"Psychiatric pharmacogenetics is still in its infancy and needs a good deal of refinement
at statistical and clinical levels," said Dr Basile. "However, we are already beginning
to look at new techniques to identify those who might be vulnerable to side-effects of
certain therapies - one of the major drawbacks of long-term treatment of
schizophrenia."
"Pharmacogenetics is the new direction for future medicines," he said. "It is currently
being applied to psychiatry as well as other fields of medicine. Theoretically, it could
break the 'trial-and-error' approach to prescribing medicines for disorders like
schizophrenia and may lead to individualized treatment based on a person's genetic
make-up."
In the past the term, pharmacogenetics, has been used to describe research into
medicinal drug levels in the body but is possible to exploit the knowledge of genetics
directly to pharmacology - the study of the action of a drug. "In looking for the
biological effect of drugs in this way, we can also find clues for the cause of disease,"
he said.
It is not only schizophrenia where pharmacogenetics shows promise. Professor Ian
Hall in the division of therapeutics at the University of Nottingham, has been
investigating respiratory genes associated with asthma that might explain why drugs to
treat asthma work better in some people than others.
Until now, although laboratory experiments have shown that variations in genes related
to asthma exist, it was not known how commonly some of these variants occur in the
UK population. Presenting the latest research results at the BPS meeting, Professor
Hall said, "We have recently found that 50% of individuals carry a novel genetic
variation in the beta2 receptor and one in five people carry a genetic variation in an
enzyme known as 5-lipoxygenase. These are likely to affect the way in which drugs
act."
Professor Hall recognises, however, that genes do not fully explain differences in
response to asthma treatment. Other factors also play an important part, such as
whether asthma patients adhere to the prescription instructions. Environmental factors
that may trigger an asthma attack, must be taken into account, as well as other diseases
that the patient may have at the same time.
"We know that variation in the human genome is very common," says Professor Hall.
"New technology enables us to study the extent to which a person's unique genetic
make-up may affect drug treatment."
There are important practical and ethical considerations. For instance, would a patient
want to know if they had a genetic variant? "Informal feedback from some of our
patients suggests that they would like to know, if it could help to explain why a
particular drug is not alleviating their asthma," said Professor Hall.
"From a practical point of view, if, in the future, it is possible to treat patients on the
basis of genetic factors, it could be cost-effective to introduce testing for genetic
variation into primary care that might affect drug treatment for a range of diseases."
Snell Communications Ltd
drug's binding site on brain cells, and the biological transport mechanisms responsible
for the action of clozapine. Two hundred patients who suffer from schizophrenia were
involved in the study and were treated with clozapine for at least three months. "The
results of the genetic analysis show for the first time that it is possible to predict in
80% of cases those patients who will respond well to clozapine. This may lead to a
simple new test to select patients most suited to this drug," said Professor Kerwin.
The study of genetic factors that influence a person's response to drug treatment -
pharamacogenetics - is now progressing rapidly. Pharmacogenetics is the focus for a
keynote lecture (6 January) being given by Professor Kerwin, and a one-day
symposium (7 January).
"One of the main aims of pharmacogenetics is predictability testing," said Professor
Kerwin. "This offers the potential to personalise therapy. Our results show how we
could, in the future, individualise psychiatric treatment in a group of people who
respond in different ways to different drugs."
The genetic basis for adverse reactions to antipsychotic drug treatment is of intense
interest to Dr Vincenzo Basile from the centre for addiction and mental health
(CAMH) at the University of Toronto in Canada, who also gave a lecture at the BPS
meeting. Dr Basile has conducted research into tardive dyskinesia (TD), a condition
that occurs in 20% - 30% of patients as a result of their treatment. In TD, a patient's
muscles, particularly those of the face and tongue, move involuntarily and abnormally,
and this distressing effect is often irreversible.
In early studies of dopamine receptors (the binding site for a chemical messenger in the
brain involved in movement) Dr Basile found that there could be a genetic association
between the action of these receptors related to drug treatment, and the development
of TD.
"Psychiatric pharmacogenetics is still in its infancy and needs a good deal of refinement
at statistical and clinical levels," said Dr Basile. "However, we are already beginning
to look at new techniques to identify those who might be vulnerable to side-effects of
certain therapies - one of the major drawbacks of long-term treatment of
schizophrenia."
"Pharmacogenetics is the new direction for future medicines," he said. "It is currently
being applied to psychiatry as well as other fields of medicine. Theoretically, it could
break the 'trial-and-error' approach to prescribing medicines for disorders like
schizophrenia and may lead to individualized treatment based on a person's genetic
make-up."
In the past the term, pharmacogenetics, has been used to describe research into
medicinal drug levels in the body but is possible to exploit the knowledge of genetics
directly to pharmacology - the study of the action of a drug. "In looking for the
biological effect of drugs in this way, we can also find clues for the cause of disease,"
he said.
It is not only schizophrenia where pharmacogenetics shows promise. Professor Ian
Hall in the division of therapeutics at the University of Nottingham, has been
investigating respiratory genes associated with asthma that might explain why drugs to
treat asthma work better in some people than others.
Until now, although laboratory experiments have shown that variations in genes related
to asthma exist, it was not known how commonly some of these variants occur in the
UK population. Presenting the latest research results at the BPS meeting, Professor
Hall said, "We have recently found that 50% of individuals carry a novel genetic
variation in the beta2 receptor and one in five people carry a genetic variation in an
enzyme known as 5-lipoxygenase. These are likely to affect the way in which drugs
act."
Professor Hall recognises, however, that genes do not fully explain differences in
response to asthma treatment. Other factors also play an important part, such as
whether asthma patients adhere to the prescription instructions. Environmental factors
that may trigger an asthma attack, must be taken into account, as well as other diseases
that the patient may have at the same time.
"We know that variation in the human genome is very common," says Professor Hall.
"New technology enables us to study the extent to which a person's unique genetic
make-up may affect drug treatment."
There are important practical and ethical considerations. For instance, would a patient
want to know if they had a genetic variant? "Informal feedback from some of our
patients suggests that they would like to know, if it could help to explain why a
particular drug is not alleviating their asthma," said Professor Hall.
"From a practical point of view, if, in the future, it is possible to treat patients on the
basis of genetic factors, it could be cost-effective to introduce testing for genetic
variation into primary care that might affect drug treatment for a range of diseases."
Snell Communications Ltd
Schizophrenia News and Current Schizophrenia Events RSSAnti-psychotic drug use in the elderly increases despite drug safety warnings
Three regulatory warnings of serious adverse events slowed the growth of use of atypical antipsychotic drugs among elderly patients with dementia, but they did not reduce the overall prescription rate of these drugs.
Looking beyond the drug receptor for clues to drug effectiveness
Antipsychotic drugs that are widely used to treat schizophrenia and other problems may not work as scientists have assumed, according to findings from Duke University Medical Center researchers that could lead to changes in how these drugs are developed and prescribed.
Severe, acute maternal stress linked to the development of schizophrenia
Pregnant women who endure the psychological stress of being in a war zone are more likely to give birth to a child who develops schizophrenia.
Unlocking mystery of why dopamine freezes Parkinson's patients
Parkinson's disease and drug addiction are polar opposite diseases, but both depend upon dopamine in the brain. Parkinson's patients don't have enough of it; drug addicts get too much of it. Although the importance of dopamine in these disorders has been well known, the way it works has been a mystery.
Human brains pay a price for being big
Metabolic changes responsible for the evolution of our unique cognitive abilities indicate that the brain may have been pushed to the limit of its capabilities. Research published today in BioMed Central's open access journal Genome Biology adds weight to the theory that schizophrenia is a costly by-product of human brain evolution.
Estrogen relieves psychotic symptoms in women with schizophrenia
When combined with antipsychotic medications, the estrogen estradiol appears to be a useful treatment in women with schizophrenia, according to a report in the August issue of Archives of General Psychiatry, one of the JAMA/Archives journals.
N.Y. Research Team Discovers How Antidepressants and Cocaine Interact with Brain Cell Targets
In a first, scientists from Weill Cornell Medical College and Columbia University Medical Center have described the specifics of how brain cells process antidepressant drugs, cocaine and amphetamines. These novel findings could prove useful in the development of more targeted medication therapies for a host of psychiatric diseases, most notably in the area of addiction.
Study Shows Promising Results in Deep Brain Stimulation for Treatment-Resistant Depression
New data from a study of patients with treatment-resistant depression who underwent deep brain stimulation (DBS) in the subcallosal cingulate region (SCG or Cg25) of the brain shows that this intervention is generally safe and provides significant improvement in patients as early as one month after treatment. The patients also experienced continued and sustained improvement over time.
Protein marker for schizophrenia risk
A protein found in immune cells may be a reliable marker for schizophrenia risk, report researchers in a new proteomics study appearing in the July issue of Molecular and Cellular proteomics.
Schizophrenia linked to dysfunction in molecular brain pathway activated by marijuana
Alterations in a molecular brain pathway activated by marijuana may contribute to the cognitive symptoms of schizophrenia, according to a report in the July issue of Archives of General Psychiatry, one of the JAMA/Archives journals.
More Schizophrenia News Articles
 | Abnormal Psychology (5th Edition) by Thomas F. Oltmanns, Robert E. Emery This new edition retains the book's engaging and innovative systems approach, integrating the biological, psychological, and social perspectives in one concurrent story. Scientific methods are presented in a clear and non-threatening manner, and are based on the most current research. Chapter topics include personality disorders, eating disorders, substance use disorders, sexual and gender... |
 | The Soloist: A Lost Dream, an Unlikely Friendship, and the Redemptive Power of Music by Steve Lopez A moving story of the remarkable bond between a journalist in search of a story and a homeless, classically trained musician—destined to be a major motion picture from DreamWorks, starring Jamie Foxx and Robert Downey Jr.When Steve Lopez saw Nathaniel Ayers playing his heart out on a two-string violin on Los Angeles’ skid row, he found it impossible to walk away. More than thirty years earlier,... |
 | Center Cannot Hold, The: My Journey Through Madness by Elyn R. Saks Elyn Saks is a success by any measure: she's an endowed professor at the prestigious University of Southern California Gould School of Law. She has managed to achieve this in spite of being diagnosed as schizophrenic and given a "grave" prognosis -- and suffering the effects of her illness throughout her life.Saks was only eight, and living an otherwise idyllic childhood in sunny 1960s Miami,... |
 | The Quiet Room: A Journey Out of the Torment of Madness by Lori Schiller, Amanda Bennett |
 | Mad In America: Bad Science, Bad Medicine, and The Enduring Mistreatment of the Mentally Ill by Robert Whitaker Hot on the heels of an optimistic film about Nobelist John Nash's schizophrenic journey comes medical journalist Robert Whitaker's disturbing exposé of the cruel and corrupt business of treating mental illness in America. Mad in America begins by surveying three centuries of mental health treatments to discover why positive outcomes for schizophrenics in the U.S. for the last 25 years have... |
 | Surviving Schizophrenia: A Manual for Families, Consumers, and Providers (4th Edition) by E. Fuller Torrey The third edition of this indispensable manual thoroughly details everything patients, families, and mental health professionals need to know about one of the most widespread and misunderstood... |
 | Abnormal Psychology in a Changing World by Jeffrey S. Nevid, Spence A. Rathus, Beverly Greene This introduction to abnormal psychology is designed to make the material more accessible and inviting to a new generation in a changing world. Noteworthy for its clear and engaging writing style that is accessible to readers, superior pedagogy, many engaging case examples and user-oriented applications, and integration of sociocultural material throughout. The authors adopt an interactionist... |
 | Is There No Place on Earth for Me? by Susan Sheehan " A brilliantly documented chronicle of young woman's long struggle with schizophrenia."-- Willard Gaylin, The New Republic"Sylvia Frumkin," highly intelligent young girl, became a schizophrenic in her late teens and spent most of the next seventeen years in anti out of mental institutions. Susan Sheehan, a talented reporter followed "Sylvia" for almost a year talking with and observing her... |
 | Stalking Irish Madness: Searching for the Roots of My Family's Schizophrenia by Patrick Tracey In this powerful, sometimes harrowing, deeply felt story, Patrick Tracey journeys to Ireland to track the origin and solve the mystery of his Irish-American family's multigenerational struggle with schizophrenia.For most Irish Americans, a trip to Ireland is often an occasion to revisit their family's roots. But for Patrick Tracey, the lure of his ancestral home is a much more powerful need: part... |
 | A Thousand Plateaus: Capitalism and Schizophrenia by Gilles Deleuze, Felix Guattari, Brian Massumi |
| © 2008 BrightSurf.com |