PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Genetic link to rapid weight gain from antipsychotics discovered

2012-07-18
(Press-News.org) July 17, 2012 – Toronto – Scientists have discovered two genetic variants associated with the substantial, rapid weight gain occurring in nearly half the patients treated with antipsychotic medications, according to two studies involving the Centre for Addiction and Mental Health (CAMH).

These results could eventually be used to identify which patients have the variations, enabling clinicians to choose strategies to prevent this serious side-effect and offer more personalized treatment.

"Weight gain occurs in up to 40 per cent of patients taking medications called second-generation or atypical antipsychotics, which are used because they're effective in controlling the major symptoms of schizophrenia," says CAMH Scientist Dr. James Kennedy, senior author on the most recent study published online in the Archives of General Psychiatry.

This weight gain can lead to obesity, type 2 diabetes, heart problems and a shortened life span.

"Identifying genetic risks leading to these side-effects will help us prescribe more effectively," says Dr. Kennedy, head of the new Tanenbaum Centre for Pharmacogenetics, which is part of CAMH's Campbell Family Mental Health Research Institute. Currently, CAMH screens for two other genetic variations that affect patients' responses to psychiatric medications.

Each study identified a different variation near the melanocortin-4 receptor (MC4R) gene, which is known to be linked to obesity.

In the Archives of General Psychiatry study, people carrying two copies of a variant gained about three times as much weight as those with one or no copies, after six to 12 weeks of treatment with atypical antipsychotics. (The difference was approximately 6 kg versus 2 kg.) The study had four patient groups: two from the U.S., one in Germany and one from a larger European study.

"The weight gain was associated with this genetic variation in all these groups, which included pediatric patients with severe behaviour or mood problems, and patients with schizophrenia experiencing a first episode or who did not respond to other antipsychotic treatments," says CAMH Scientist Dr. Daniel Müller. "The results from our genetic analysis combined with this diverse set of patients provide compelling evidence for the role of this MC4R variant. Our research group has discovered other gene variants associated with antipsychotic-induced weight gain in the past, but this one appears to be the most compelling finding thus far."

Three of the four groups had never previously taken atypical antipsychotics. Different groups were treated with drugs such as olanzapine, risperidone, aripiprazole or quetiapine, and compliance was monitored to ensure the treatment regime was followed. Weight and other metabolic-related measures were taken at the start and during treatment.

A genome-wide association study was conducted on pediatric patients by the study's lead researcher, Dr. Anil Malhotra, at the Zucker Hillside Hospital in Glen Oaks, NY. In this type of study, variations are sought across a person's entire set of genes to identify those associated with a particular trait. The result pointed to the MC4R gene.

This gene's role in antipsychotic-induced weight gain had been identified in a CAMH study published earlier this year in The Pharmacogenomics Journal, involving Drs. Müller and Kennedy, and conducted by PhD student Nabilah Chowdhury. They found a different variation on MC4R that was linked to the side-effect.

For both studies, CAMH researchers did genotyping experiments to identify the single changes to the sequence of the MC4R gene – known as single nucleotide polymorphisms (SNPs) – related to the drug-induced weight gain side-effect.

The MC4R gene encodes a receptor involved in the brain pathways regulating weight, appetite and satiety. "We don't know exactly how the atypical antipsychotics disrupt this pathway, or how this variation affects the receptor," says Dr. Müller. "We need further studies to validate this result and eventually turn this into a clinical application."

###

The CAMH researchers were supported by a Canadian Institutes of Health Research (CIHR) grant and a NARSAD grant from the U.S. Brain and Behavior Fund.

Media Contact: Michael Torres, Media Relations, CAMH; 416-595-6015

The Centre for Addiction and Mental Health (CAMH) is Canada's largest mental health and addiction teaching hospital, as well as one of the world's leading research centres in the area of addiction and mental health. CAMH combines clinical care, research, education, policy development and health promotion to help transform the lives of people affected by mental health and addiction issues.

CAMH is fully affiliated with the University of Toronto, and is a Pan American Health Organization/World Health Organization Collaborating Centre.

END



ELSE PRESS RELEASES FROM THIS DATE:

Poisoning from industrial compounds can cause similar effects to ALS

2012-07-18
Researchers from the Bellvitge Biomedical Research Institute (IDIBELL) at the University of Barcelona (UB) have coordinated a research into how the IDPN nitrile causes neurological syndromes similar to those of the amyotrophic lateral sclerosis (ALS), a severe neuromuscular degenerative disease. The study, led by Jordi Llorens, has been recently published in Neuropathology and Applied Neurobiology journal. Nitriles, chemical compounds containing the cyano (-CN) group, are ubiquitous in nature and have diverse applications in industry. In nature they appear as cyanogenic ...

Helping pigs to digest phosphorus

2012-07-18
URBANA -- Phosphorus is a vital nutrient for pig growth, but pigs do not always digest it well. Research conducted at the University of Illinois has determined how adding various levels of the enzyme phytase to the diet improves how pigs digest the phosphorus in four different feed ingredients. Improving phosphorus digestibility has positive implications for producers' bottom lines as well as for the environment. "The majority of the phosphorus in plant feed ingredients is bound in phytate," said U of I animal sciences professor Hans Stein. "It is difficult for pigs to ...

Clemson researcher: Humanizing computer aids affects trust, dependence

2012-07-18
CLEMSON — Computerized aids that include person-like characteristics can influence trust and dependence among adults, according to a Clemson University researcher. A recently published study by Clemson University psychology associate professor Richard Pak examined how decision-making would be affected by a human-like aid. The study focused on adults' trust, dependence, and performance while using a computerized decision-making aid for persons with diabetes. The study is one of the first to examine how the design of decision-support aids on consumer devices can influence ...

Physical health problems substantially increase use of mental health services, study shows

2012-07-18
CORVALLIS, Ore. – People who experience a physical health problem, from diabetes and back pain to cancer or heart disease, are three times more likely to seek mental health care than patients who report having no physical ailment, according to a new study by Oregon State University researchers. The study, which is now online in the journal Health Services Research, indicates there is a need for better-coordinated care between physical and mental health providers. It is the first nationally representative study that statistically shows a major link between physical health ...

Study: Children abused by parents face increased cancer risk

2012-07-18
WEST LAFAYETTE, Ind. - Frequent abuse by a parent can increase a child's cancer risk in adulthood, and the effects are especially significant when mothers abuse their daughters and fathers abuse their sons, according to new research from Purdue University. "People often say that children are resilient and they'll bounce back, but we found that there are events that can have long-term consequences on adult health," said Kenneth Ferraro, distinguished professor of sociology and director of Purdue's Center on Aging and the Life Course. "In this case, people who were frequently ...

Glyphosate-resistant 'superweeds' may be less susceptible to diseases

2012-07-18
WEST LAFAYETTE, Ind. - Scientists searching for clues to understand how superweeds obtain resistance to the popular herbicide glyphosate may have been missing a critical piece of information, a Purdue University study shows. Glyphosate, the active ingredient in the weed killer sold under the name RoundUp, is the most widely used herbicide in the United States, but some plants have grown resistant to it. This has caused farmers to turn to additional herbicides. While the mechanisms that have led to resistance are not fully known, Bill Johnson, a professor of weed science; ...

'Sifting' liquid at the molecular level

2012-07-18
Drexel University engineers continue to drive research into the use of carbon nanotubes, straw-like structures that are more than 1,000 times thinner than a single human hair. Their most recent development uses the tiny tubes to separate liquids within a solution. The researchers have shown that individual carbon nanotubes can act as a separation channel that would force two differing molecules to separate as easily as oil and water. For example, the molecules that comprise two chemically distinct liquids will interact differently with the walls of the nanotube as the ...

Autonomous robot maps ship hulls for mines

2012-07-18
CAMBRIDGE, Mass. — For years, the U.S. Navy has employed human divers, equipped with sonar cameras, to search for underwater mines attached to ship hulls. The Navy has also trained dolphins and sea lions to search for bombs on and around vessels. While animals can cover a large area in a short amount of time, they are costly to train and care for, and don't always perform as expected. In the last few years, Navy scientists, along with research institutions around the world, have been engineering resilient robots for minesweeping and other risky underwater missions. The ...

Nanoscale scaffolds and stem cells show promise in cartilage repair

2012-07-18
Johns Hopkins tissue engineers have used tiny, artificial fiber scaffolds thousands of times smaller than a human hair to help coax stem cells into developing into cartilage, the shock-absorbing lining of elbows and knees that often wears thin from injury or age. Reporting online June 4 in the Proceedings of the National Academy of Sciences, investigators produce an important component of cartilage in both laboratory and animal models. While the findings are still years away from use in people, the researchers say the results hold promise for devising new techniques to ...

Revised geographic adjustments could improve accuracy of Medicare payments, will not solve access, quality problems

2012-07-18
WASHINGTON — Changing the way that Medicare payments are adjusted to account for regional variations in the cost of providing care as recommended by a previous report from the Institute of Medicine would result in payment increases for some hospitals and practitioners and decreases for others, concludes the Phase II report from the IOM study. Geographic adjustments should be used to ensure the accuracy of payments, said the committee that wrote the report, but they are not optimal tools to tackle larger national policy goals such as improving access to care in medically ...

LAST 30 PRESS RELEASES:

Pink skies

Monkeys are world’s best yodellers - new research

Key differences between visual- and memory-led Alzheimer’s discovered

% weight loss targets in obesity management – is this the wrong objective?

An app can change how you see yourself at work

NYC speed cameras take six months to change driver behavior, effects vary by neighborhood, new study reveals

New research shows that propaganda is on the rise in China

Even the richest Americans face shorter lifespans than their European counterparts, study finds

Novel genes linked to rare childhood diarrhea

New computer model reveals how Bronze Age Scandinavians could have crossed the sea

Novel point-of-care technology delivers accurate HIV results in minutes

Researchers reveal key brain differences to explain why Ritalin helps improve focus in some more than others

Study finds nearly five-fold increase in hospitalizations for common cause of stroke

Study reveals how alcohol abuse damages cognition

Medicinal cannabis is linked to long-term benefits in health-related quality of life

Microplastics detected in cat placentas and fetuses during early pregnancy

Ancient amphibians as big as alligators died in mass mortality event in Triassic Wyoming

Scientists uncover the first clear evidence of air sacs in the fossilized bones of alvarezsaurian dinosaurs: the "hollow bones" which help modern day birds to fly

Alcohol makes male flies sexy

TB patients globally often incur "catastrophic costs" of up to $11,329 USD, despite many countries offering free treatment, with predominant drivers of cost being hospitalization and loss of income

Study links teen girls’ screen time to sleep disruptions and depression

Scientists unveil starfish-inspired wearable tech for heart monitoring

Footprints reveal prehistoric Scottish lagoons were stomping grounds for giant Jurassic dinosaurs

AI effectively predicts dementia risk in American Indian/Alaska Native elders

First guideline on newborn screening for cystic fibrosis calls for changes in practice to improve outcomes

Existing international law can help secure peace and security in outer space, study shows

Pinning down the process of West Nile virus transmission

UTA-backed research tackles health challenges across ages

In pancreatic cancer, a race against time

Targeting FGFR2 may prevent or delay some KRAS-mutated pancreatic cancers

[Press-News.org] Genetic link to rapid weight gain from antipsychotics discovered