May 22, 2007

Is Childhood Bipolar Disorder Overdiagnosed in the US?

New Scientist magazine has an indepth article that covers the issue of the increasing tendency for atypical American children to be diagnosed with 'juvenile bipolar disorder'.

The article suggests that young children are being increasingly diagnosed with bipolar disorder in the US, despite the fact that there is limited evidence for its validity and disagreement about its symptoms.

The diagnosis of childhood bipolar disorder is - other experts have noted - has many issues associated with it.

Part of the issue is that children often are not able to report their thoughts and emotions adequately, and equally importantly there are many different forms of distress get expressed as 'misbehaviour', making it hard to distinguish between different causes.

Read the full article: Bipolar children - is the US overdiagnosing?

Posted by szadmin at 9:27 AM | Comments (0)

May 14, 2007

Bipolar Disorder Medication Options

The psychiatrist at the blog "corpus callosum" writes about different bipolar disorder medication options that are covered in Medscape this month. Interesting reading - and commentary following the discussion. Medscape requires free registration for access to the articles.

Read the article: Bipolar Disorder Medications

Posted by szadmin at 10:26 AM | Comments (1)

May 9, 2007

Valproate Used During Pregnancy Linked To Lower IQ in Children

We've seen studies that have investigated Valproate in the treatment of bipolar disorder - but we don't know whether this practice has spread, and if so how frequently it is used off-label in this application. Because of the research that has been done in this area, we thought this would be of interest.

Children of women who took the drug valproate during pregnancy appear to be at a greater risk for lower IQ, according to recent research. The study looked at IQ test results for 187 two-year-old children of mothers who took the epilepsy drugs carbamazepine, lamotrigine, phenytoin, or valproate during pregnancy.

According to the study, 24 percent of the children of mothers who took valproate showed an IQ in the mental retardation range, compared to 12 percent for carbamazepine, nine percent for lamotrigine, and 12 percent for phenytoin. On an IQ test, children whose mothers took carbamazepine scored an average of 93 points, compared to 93 for those who took phenytoin, 96 for lamotrigine, and 84 for valproate. The scores were adjusted to account for the mother's IQ and the drug dosage.

The study also found that children with higher levels of valproate in their blood had lower IQ scores.

"Further studies are needed to confirm these findings, examine IQ at older ages, and to determine the risks for other epilepsy drugs," said study author Kimford Meador, MD, of the University of Florida in Gainesville, FL, and Fellow of the American Academy of Neurology. "However, our findings are consistent with other studies, which have shown valproate poses an increased risk for fetal death and birth defects, and have suggested the drug may harm cognitive development."

The study also found children's IQ was related to their mother's IQ for every epilepsy drug except valproate.

Meador is recommending doctors talk with their patients about the risks associated with valproate. "Although valproate remains an important treatment option in women who aren't able to use other epilepsy drugs, valproate should not be used as the drug of first choice for women of child bearing potential, and when used, its dosage should be limited if possible," said Meador.

The study was supported by the National Institute of Neurological Disorders and Stroke at the National Institutes of Health.This research was presented at the American Academy of Neurology's 59th Annual Meeting in Boston, April 28 -- May 5, 2007.

Posted by szadmin at 10:47 AM | Comments (1)

May 8, 2007

4 Percent of US Adults have Bipolar Disorder

Approximately 4.4 percent of U.S. adults may have some form of bipolar disorder during some point in their lifetime, including about 2.4 percent with a "sub-threshold" condition, according to an article in the May issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

Individuals with bipolar disorder tend to fluctuate between periods of mania -- an inappropriately elevated mood, characterized by impulsive behavior and an increased activity level -- and periods of depression. They are at increased risk of suicide and other medical problems, such as cardiovascular disease, according to background information in the article. Previously, researchers estimated that about 1 percent of adults had bipolar disorder. But evidence indicates that current diagnostic criteria may be too narrow to effectively detect bipolar disorder in the general population, and that a broader definition of bipolar spectrum disorder would identify many more individuals with bipolar symptoms, the authors note.

Kathleen R. Merikangas, Ph.D., National Institute of Mental Health, Bethesda, Md., and colleagues estimated the national prevalence of bipolar disorder using data from 9,282 individuals chosen to represent the general population. The researchers conducted interviews between February 2001 and April 2003 to assess the presence of bipolar disorder and other psychiatric conditions. Participants were classified as having bipolar disorder I, characterized by at least one episode of mania and one of depression; bipolar disorder II, requiring an episode of depression plus hypomania, a milder form of mania that does not require hospitalization; and a milder, sub-threshold bipolar disorder that involves hypomania with or without depression, otherwise classified as bipolar disorder "not otherwise specified" in the current diagnostic nomenclature of the American Psychiatric Association.

The study found that:

* A total of 1.0 percent of participants had bipolar disorder I and 1.1 percent had bipolar disorder II in their lifetimes; in the previous 12 months, 0.6 percent had bipolar disorder I, 0.8 percent bipolar disorder II and 1.4 percent sub-threshold manifestations of bipolar disorder.
* Symptoms began at age 18.2 years for bipolar disorder I, 20.3 years for bipolar disorder II and 22.2 years for sub-threshold bipolar disorder
* 95.8 to 97.7 percent of those with bipolar disorder and 88.4 percent of those with sub-threshold bipolar disorder also had another psychiatric condition, such as an anxiety disorder or substance use disorder, which is a frequent complication of bipolar illness.
* The majority of those with lifetime bipolar disorder (80.1 percent) received treatment, including 69.3 percent of those with sub-threshold bipolar disorder; most of those people sought treatment for the depression rather than for the manic symptoms of bipolar disorder.
* However, over the previous 12 months, only 25 percent of those with bipolar disorder I, 15.4 percent with bipolar disorder II and 8.1 percent with sub-threshold bipolar disorder received appropriate medication

"The present results reinforce the argument of other researchers that clinically significant sub-threshold bipolar disorder is as least as common as threshold bipolar disorder," the authors write. "Although most individuals with bipolar disorder receive treatment owing to co-morbid disorders, the lack of recognition of their underlying bipolarity leads to only a few receiving appropriate treatment." The findings suggest that a substantial proportion of those diagnosed with major depression may actually have a form of bipolar disorder.

More individuals with other psychiatric disorders should also be screened for bipolar disorder, the authors conclude. "Additional research is needed to resolve uncertainty regarding the most appropriate threshold and boundary distinctions for bipolar disorder. This uncertainty remains a major impediment to advancing the understanding of the bipolar disorder spectrum in the population."


Source: Archives of General Psychiatry. 2007;64:543-552

Posted by szadmin at 9:17 AM | Comments (0)

Bipolar Disorder Genetic Basis Identified by First Genome-wide study of illness

The likelihood of developing bipolar disorder depends in part on the environment, but also a genetic risk based on the combined, small effects of variations in many different genes in the brain, none of which is powerful enough to cause the disease by itself, a new study shows. However, targeting the enzyme produced by one of these genes could lead to development of new, more effective medications. The research was conducted by scientists at the National Institutes of Health's National Institute of Mental Health (NIMH), with others from the Universities of Heidelberg and Bonn and a number of U.S. facilities collaborating in a major project called the NIMH Genetics Initiative.

The study is the first to scan virtually all of the variations in human genes to find those associated with bipolar disorder. Results were published online May 8 in Molecular Psychiatry by Amber E. Baum, PhD, lead researcher Francis J. McMahon, MD, and colleagues.

"This is an example of how advances in genetics research feed into practical applications. This research would not have been possible a very few years ago. We now have a new molecular target scientists can investigate in their search for better medications for bipolar disorder," said NIH Director Elias A. Zerhouni, MD.

About 5.7 million American adults have bipolar disorder, which also is called manic-depressive illness. Symptoms include extremes in mood, from pronounced over-excitement and elation, often coupled with severe irritability, to depression. Children also may have the condition, usually in a more severe form than adults.

"We're beginning to get a foothold on the genetics of this complex brain disorder," said NIMH Director Thomas R. Insel, MD.

Most people occasionally have mood swings, but the shifts that occur in bipolar disorder, and the changes in behavior and energy level that accompany them, are sometimes disabling. Lithium and the other mood-stabilizing medications used to treat the condition help many patients.

But some people do not respond to these medications, and clinicians need more options so that they can tailor treatments to each patient. People inherit different gene variations, which may influence whether or not they respond to a given medication. Identifying and targeting these variations could help scientists develop additional medication options that take these differences into account.

One of the genes the researchers correlated with the disorder, DGKH, is active in a biochemical pathway through which lithium is thought to exert its therapeutic effects. The gene produces an enzyme (diacylglycerol kinase eta) that functions at a point closer to the root of the lithium-sensitive pathway than does the protein that lithium is thought to target. Scientists can now try to develop more effective medications by focusing on new compounds that act on the DGKH enzyme or regulate how much of the enzyme is produced. The DGKH gene is on chromosome 13.

Several other genes detected in the study produce proteins involved in this and other biochemical pathways thought to play a role in bipolar disorder. Understanding the effects that variations of these genes have on brain-cell function could lead to explanations of how they contribute to the condition and how it might be better prevented or treated.

"Treatments that target just a few of these genes or the proteins they make could yield substantial benefits for patients. Lithium is still the primary treatment for bipolar disorder, but DGKH is a promising target for new treatments that might be more effective and better tolerated," McMahon said.

The finding was enabled by recent genetics technology that allows researchers to scan, in a single experiment, thousands of genes for variations. Everyone has the same genes, but variations in them influence whether or not a person gets a specific disease. In this study, researchers compared variations found in the scans of 413 adults who had bipolar disorder with variations found in the scans of 563 healthy adults.

By pooling the genetic material of the adults with bipolar disorder, the U.S. researchers were able to scan the entire group at a small fraction of the cost of scanning each person's material individually. The genetic material of the healthy group was pooled and scanned separately, again at a fraction of the cost of individual scans. The researchers then zeroed in on the gene variations that occurred more often in the people with bipolar disorder and examined them individually.

An important issue in genetics research is that findings correlating specific genes with specific diseases in one population may not apply to other populations. This study addressed that issue by focusing on US participants of European ancestry, then repeating the study in a large group of patients in Germany. Similar outcomes were found in both populations, strengthening the validity of the results. A subsequent study is examining whether the results apply to other populations, and will look for common variations among them.

Posted by szadmin at 9:14 AM | Comments (0)