Bipolar disorder drugs may 'tweak' genes affecting brain

April 25, 2013 by Barbara Bronson Gray, Healthday Reporter
Bipolar disorder drugs may 'Tweak' genes affecting brain
Study offers clues on causes of condition and how commonly prescribed meds work.

(HealthDay)—Medications taken by people with bipolar disorder may actually be nudging hundreds of genes that direct the brain to behave more normally, according to new research.

The study suggests that activate a wide range of genes, changing their function, said lead author Dr. Melvin McInnis.

"A gene's activity in any given cell will vary depending on what it's exposed to," said McInnis, a professor of bipolar disorder and depression at the School of Medicine at the University of Michigan.

It's not often that scientists stumble upon something in research that they totally weren't expecting to see. "It was a major surprise to us that people treated with an antipsychotic [medication] had changes in the pattern," McInnis said.

The findings could help point the way to new gene-targeted and stem cell therapies, and provide valuable insight into what causes manic-depressive , he added.

However, a genetics expert not connected to the study was more cautious about drawing implications from its findings.

Bipolar disorder, also known as manic-depressive illness, affects about 5.7 million American adults, or about 2.6 percent of the U.S. population aged 18 and older, according to the U.S. National Institute of Mental Health (NIMH). The brain disorder causes severe and unusual shifts in mood, energy, activity levels, and the ability to carry out routine daily tasks.

The new research, published in a recent issue of the journal Bipolar Disorders, involved examining 26 brains donated to a nonprofit brain bank. Fourteen of the brains were from people who had bipolar disorder. Of those, seven were from people who had been taking one or more antipsychotic medications—such as , and —when they died. Twelve brains were from those with no mental health condition.

In comparing the brains, the scientists observed that the genes of those that had been exposed to antipsychotics at the time of death or during their lifetime were similar to those from people who did not have bipolar disorder. This suggests that the drugs may normalize or suppress the kinds of brain pathology one would expect in bipolar disorder, according to the researchers.

The study also supports the idea that the ability of cells to effectively communicate with each other may be impaired in people with bipolar disorder. The researchers found that the brains of people who were taking antipsychotics and those who did not have bipolar disorder showed striking similarities in how their brains relayed signals between cell gaps, or synapses, and on high-speed neuronal "freeways" called the nodes of Ranvier.

While antipsychotic medications can often be effective in moderating the effects of bipolar disorder, the side effects are often difficult for people to deal with. These include metabolic syndrome —a combination of symptoms that increase the risk of developing cardiovascular disease and diabetes—as well as weight gain, increased blood sugar levels, and tremors, McInnis said.

However, one expert expressed some concerns about the study.

"It's still not known if these changes just happen to occur or play a key role in the therapeutic effect," said Dr. Francis McMahon, chief of the human genetics branch at the NIMH Intramural Research Program.

McMahon also noted that the researchers don't have data on what medications the brains were exposed to during their lifetimes. "Patients [with bipolar disorder] are exposed to antidepressants, drugs of abuse, and other medications, and we don't have medication exposure data on the brains [of the people without ]."

For his part, study author McInnis said the research represents a step toward a radical evolution in the design of drugs for psychiatric conditions by the pharmaceutical industry.

"A lot of these psychiatric illnesses fluctuate, but now we give medications at a constant rate, almost as if we were giving a diabetic the same amount of insulin no matter what the person's blood sugar is," McInnis said. "Medications as we know them will change based on our understanding of the biological mechanisms behind disease."

Explore further: Do drugs for bipolar disorder 'normalize' brain gene function? Study suggests so

More information: Learn more about bipolar disorder from the U.S. National Library of Medicine.

Related Stories

Do drugs for bipolar disorder 'normalize' brain gene function? Study suggests so

April 11, 2013
Every day, millions of people with bipolar disorder take medicines that help keep them from swinging into manic or depressed moods. But just how these drugs produce their effects is still a mystery.

Lawson researcher sings the baby blues

August 22, 2012
The impact of bipolar disorder during pregnancy has been hotly contended among the research community. Now, a new study from Lawson Health Research Institute and Western University is sorting out the debate and calling for ...

Scientists pinpoint gene variations linked to higher risk of bipolar disorder

October 10, 2012
(Medical Xpress)—Scientists from the Florida campus of The Scripps Research Institute (TSRI) have identified small variations in a number of genes that are closely linked to an increased risk of bipolar disorder, a mental ...

New study aims to improve long-term treatment for patients with bipolar disorder

May 24, 2011
Patients with bipolar disorder may be eligible for a new clinical research study comparing two medications -- quetiapine (Seroquel), a widely prescribed second-generation antipsychotic mood-stabilizing medication, and lithium, ...

Recommended for you

Babies' babbling betters brains, language

January 18, 2018
Babies are adept at getting what they need - including an education. New research shows that babies organize mothers' verbal responses, which promotes more effective language instruction, and infant babbling is the key.

College branding makes beer more salient to underage students

January 18, 2018
In recent years, major beer companies have tried to capitalize on the salience of students' university affiliations, unveiling marketing campaigns and products—such as "fan cans," store displays, and billboard ads—that ...

Inherited IQ can increase in early childhood

January 18, 2018
When it comes to intelligence, environment and education matter – more than we think.

Modulating molecules: Study shows oxytocin helps the brain to modulate social signals

January 17, 2018
Between sights, sounds, smells and other senses, the brain is flooded with stimuli on a moment-to-moment basis. How can it sort through the flood of information to decide what is important and what can be relegated to the ...

Baby brains help infants figure it out before they try it out

January 17, 2018
Babies often amaze their parents when they seemingly learn new skills overnight—how to walk, for example. But their brains were probably prepping for those tasks long before their first steps occurred, according to researchers.

Reducing sessions of trauma-focused psychotherapy does not affect effectiveness

January 17, 2018
Posttraumatic Stress Disorder (PTSD) patients treated with as few as five sessions of trauma-focused psychotherapy find it equally effective as receiving 12 sessions.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.