How Genes Influence Bipolar Disorder
In genetic testing, bipolar patients showed an increased expression of genes associated with the condition. Genetic predisposition doesnt necessarily mean one is guaranteed to have bipolar disorder, but it does increase the odds of diagnosis. Genetics account for between 6080% of the cause of bipolar disorder.
However, it is important to distinguish between the potential for genetic exposure to a condition and the likelihood of developing it. Even if you have a family member with bipolar disorder, it doesnt guarantee that you will develop it yourself. When we consider the plethora of genetic material we are connected to from both sides of our family of origin, it is statistically possible to have any number of manifestations. Scientists are exploring potential abnormalities in particular gene sequences that may influence the development of bipolar.
What Age Does Bipolar Start
There is no age at which bipolar symptoms will show. It can happen at any time, from childhood to old age. Though when it comes to children and adolescents, it’s important to note that there are a few different ways bipolar symptoms can present. Some kids who have bipolar disorder may not show signs until they’re older, while others’ symptoms are more obvious from an early age. It all depends on the child and the severity of their illness some children might have very mild lows , while others suffer from severe highs throughout their childhoods.
New Study Provides First Look At Gene Expression In Brains Of People With Bipolar Disorder
The findings, published today in Nature Neuroscience, represent the first time that researchers have been able to apply the discipline and tools of genetic research to brain samples from hundreds of patients with bipolar disorder , a chronic, often debilitating, almost always incurable behavioral syndrome. The findings suggest that bipolar disorder may stem from chemical and structural changes in brain cells that affect how they communicate with each other.
“This is the first deep dive into the molecular biology of the brain in people who died with bipolar disorderstudying actual genes, not urine, blood or skin samples,” said Dr. Thomas Hyde of the Lieber Institute and a co-author of the paper. “If we can figure out the mechanisms behind BD, if we can figure out what’s wrong in the brain, then we can begin to develop new targeted treatments of what has long been a mysterious condition.”
Because the brain is a complex organ with many distinct anatomical and functional regionsand varying patterns of gene expressionscientists narrowed their study to two key regions of the limbic system, which plays a vital role in regulating behavior, emotion and memory. The regions were the amygdala and the subgenual anterior cingulate cortex , which evidence strongly suggests underlie mood regulation and the pathophysiology of bipolar disorder.
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Knowing That Bipolar Disorder Is Strongly Genetic Means Nobody Is At Fault
New therapy patients and their family members can have any number of reactions when first introduced to the diagnosis of bipolar disorder. Disbelief and denial are typical responses, but they may also believe they did something bad to bring bipolar into their lives. Or that there is something distinctly flawed with who they are as human beings. They may have carried a sense of shame for years, not fully prepared to deal with the reality of a chronic mental illness. But the truth is, nobody is at fault for having bipolar disorder.
Thats because the foundations of bipolar are believed to be largely genetic, which is the strongest and most consistent risk factor for the disease . As bipolar disorder is passed through family generational lines, it appears to affect how the brain is formed to handle mood regulation. So when attempting to uncover bipolar, its vital to understand the familys mental health history to know whether an individual may be predisposed to the disorder. If anyone in the family tree has experienced mood swings, particularly in the closest genetic relatives, a person could certainly be predisposed to bipolar disorder. Then a more precise inquiry can discover where bipolar symptoms may have been hiding in that individuals own life history.
Is Bipolar More Common In Males Or Females
Bipolar disorder is three times more common in women than in men. Women are also much more likely to be diagnosed with the condition as children, while men are more likely to develop it as adults. In fact, 60 % of all people diagnosed with bipolar disorder are female. This could be because the classic symptoms of bipolar disorder are more common in women, such as extreme sadness and irritability. Men and women do experience the disorder in different ways, though. Women are more likely to experience extreme highs and extreme lows, while men are more likely to have regular mood swings..
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Understanding The Family Ties
Bipolar disorder is a complex condition involving untold genes, and family history does not necessarily mean a person will inherit the illness. But it does play a strong role. According to NARSAD , children of one parent with bipolar carry a 15 percent to 30 percent risk of themselves developing the illness. Those with two parents with bipolar have a 50 percent to 75 percent risk of getting it.
Bipolar disorder is one of the most clearly heritable disorders there is, says Samuel H. Barondes, MD, director of the Center for Neurobiology and Psychiatry at the University of California, San Francisco. The evidence is absolutely overwhelming, and there is not much evidence that nurture has any influence at all.
Although the genetic component is undeniable, the relationship is far from straightforward, he continues. There are an untold number of genes responsible for bipolar disorder, many of them overlapping with schizophrenia.
Roger McIntyre, MD and associate professor of psychiatry and pharmacology at the University of Toronto says this about the genetic component: Most individuals who have bipolar disorder can identify someone else in their family who also has a psychiatric disorder. As a point of fact, the other psychiatric disorder is not always bipolar disorder, he says. Major Depression, anxiety disorders, substance abuse disorders and ADHD are more commonly encountered than is bipolar. People need to think not only about bipolar, but other conditions as well.
How Often Does Bipolar Disorder Run In Families
The most substantial evidence for a genetic cause of bipolar disorder comes from studies of identical twins. If a person has an identical twin with bipolar disorder, their risk of developing it is as high as 80%.3 Identical twins have the same genes and therefore have the same genes acting in combination.
If someone has a parent, sibling, or child with bipolar disorder, their risk is ten times higher than that of the general population.3 However, their overall risk is only 5-10%. Some common genes only contribute to a small risk of bipolar disorder. Most people with a genetic predisposition to it do not end up developing bipolar disorder. Additionally, those with only a distant relative with bipolar disorder, such as an uncle, cousin, or grandparent, are less likely to develop it than people with a closer relative who have the condition.
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Can Environmental Stress Increase The Risk Of Bipolar Disorder
People are sometimes diagnosed with bipolar following a stressful or traumatic event in their lives. These environmental triggers can include seasonal changes, holidays, and major life changes such as starting a new job, losing a job, going to college, family disagreements, , or a death in the family. Stress, in and of itself, does not cause bipolar disorder , but in people with the biological vulnerability to bipolar disorder, having effective skills for managing life stresses can be critical to a healthy lifestyle in order to avoid things that can aggravate the illness .
What Does It Mean To Have A Genetic Predisposition
If a trait or condition is genetic, or hereditary, that means that it can pass from parents to offspring via their genes. As we briefly mentioned, every child gets one chromosome from either parent, which means children are born with half of their parents genes.
A genetic predisposition means that the likelihood of developing a trait is linked to a gene or set of genes. If a parent has a gene that always codes for trait X, their child will have a genetic predisposition to develop trait X. However, this is only a likelihood, not a guarantee its possible to inherit a gene that is never expressed.
One famous example here are the BRCA1 and BRCA2 genes. Mutations in either gene greatly increase the risk of both breast and ovarian cancer. Its estimated that in about 5% to 10% of cases, these mutations are hereditary, which means a mother with breast cancer may pass on an increased risk of developing breast cancer. However, not every child of a parent with a BRCA mutation will develop breast cancer.
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Can You Have Bipolar Without Family History
Most people with bipolar disorder have a family history of the disorder. That does not mean, however, the condition cannot develop in someone who does not have a family history of bipolar disorder. Exactly how common bipolar disorder is in people with no family history is unclear. What is clear, however, is that the eventual onset of bipolar disorder can often be predicted by a persons experiences in early life. For example, if a young person has had a very stressful, chaotic or abusive upbringing, he or she may be at higher risk for onset of bipolar disorder..
Generation To Generation Family Members Observe And Reflect On Patterns Of Bipolar
For some families, bipolar disorder runs through the generations as invariably as freckles or cleft chins appear in other family trees. Even so, looking for your familys source of bipolar disorder can be a little like searching for the headwaters of the Nile. You start backtracking through the generations and suddenly realize that the quirky behavior you once brushed aside as your grandmothers eccentricity was really a signpost.
If only you had recognized her outlandishness or rage for what it wasthe genetic source of your own bipolar disorder. You might have been more tolerant of her. Perhaps you wouldnt have distanced yourself so much. At the very least, you might have asked some questions.
Unfortunately, many people never think to connect the dots in their familys history of wellness until the day a family member is diagnosed with bipolar. Suddenly, it hits like a ton of brickseverything falls into place. As one mother describes it, it wasnt until her son was diagnosed that she recognized her own illness. Oh my gosh, thats whats the matter with me!
This experience was related in one way or another by several individuals interviewed for this story. Jolted by the diagnosis of a child or a grandchild, an older family member may reluctantly acknowledge the symptoms as his or her own. Sometimes, it comes as a bolt of self-recognition other times, its a case of reluctant consent, a muttered admission, Yes, thats me.
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Risk Factors For Bipolar Disorder
Unfortunately, researchers thus far have been unable pinpoint a single cause of bipolar disorder. Instead, bipolar seems to be multifactorial, meaning a combination of genetic and environmental factors are most likely at play.
That said, most recent science suggests that bipolar has a genetic component. While which genes and how many are involved is still up in the air, the evidence from family studies is fairly conclusive. But genetics arent the only risk factor for developing bipolar.
For instance, some brain studies suggest that individuals with bipolar have different brain structures. However, this science is still in its infancy much more research is needed to reach a definitive conclusion on which structures are involved, and to what degree.
And of course, we have the environmental factors. In some cases, its hard to determine which came first: the bipolar disorder, or the risk factor. For instance, illegal substance abuse and alcohol dependence are common in individuals with bipolar. But while some individuals appear to develop bipolar after they take drugs, others use the drugs to treat their symptoms.
Additionally, anxiety disorders and ADHD are more likely to occur in an individual who has bipolar disorder. However, here too, more research is needed.
Is Bipolar Disorder Genetic
Bipolar disorder is one of the most heritable mental health conditions, with family history being a significant risk factor.
Individuals who have a first-degree relative with bipolar disorder have an increased risk. Research shows that children who have a parent with bipolar disorder are 10 times more likely to develop the condition.
Though there are challenges, researchers continue to explore the association between genetics and bipolar disorder.
Problems with calcium signaling are associated with the condition. Genes such as CACNA1C and ANK3, which contribute to the regulation of calcium, may play a role, though this is still unclear.
Other possible gene connections include Neuregulin 1 and G72/30. They are tied to dopamine and serotonin pathways. Dopamine and serotonin are neurotransmitters involved in communication between nerve cells. Both neurotransmitters are associated with mood regulation.
Although it’s clear that there is a strong genetic component in the development of bipolar disorder, the complexities continue to be explored.
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The Common Diseasecommon Variant Hypothesis
KEY CONCEPT 5. Common complex disorders.
Some common medical conditions, such as diabetes or high-blood pressure, are believed to be caused by genetic and environmental factors. Therefore, the transmission in families might not follow a simple Mendelian mode of transmission. According to this model, an individual might not manifest the disease, even though he or she carries a risk mutation, if the environmental exposure has not occurred.
Summary And Future Directions In Genetic Studies Of Bipolar Disorder
Scientists and clinicians who may have hoped that one or a few genes would eventually be identified that, would explain the majority of risk for bipolar disorder must, face the reality that there are likely to be many genes of relatively small effect, involved in bipolar disorder, and the genetic dissection of this disorder will be a subtle and complex process. Genetic testing for bipolar disorder will likely ultimately require careful weighing of the presence or absence of many gene variants, when counseling is being done at the population level. As specific genes are clearly identified to play a role in bipolar disorder, it remains quite possible that, within specific families or clusters, genes of moderate effect will be discovered, but, we must face the fact that, thus far, no clear bipolar disease causing variant, has been discovered in any family studied. In the next, decade, a feasible goal might, be to clearly implicate at, least a handful of genes , from which the biochemical pathways underlying the disease can be more thoroughly studied at the level of cell biology and physiology. Such approaches may yield clear pharmacologic targets which can intervene in disease processes that have their origin in genetic risk variants, at. times by acting on an enzyme or protein that is part, of the biochemical pathway rather than on the gene or gene product, itself.127
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Who Is At Risk Of Bipolar Disorder
More than 10 million Americans have bipolar disorder. Bipolar disorder affects men and women equally, as well as all races, ethnic groups, and socioeconomic classes.
Although men and women appear to be equally affected by bipolar disorder, rapid cycling is seen more often in women. Women also tend to experience more depressive and mixed state episodes than do men. A man’s first experience with bipolar disorder may be in a manic state women tend to first experience a depressive state.
Bipolar disorder can present itself at any age, but typically, onset occurs around age 25.
How Much Do Genes Affect Bipolar Disorder
When determining the likelihood that a persons genes have an influence on a specific physical or psychological problem, researchers study twins and adopted children. These two groups can help minimize other variables like environmental and developmental factors. Identical twins have very similar genes, while paternal twins can be as genetically distinct as any siblings. If one identical twin has the disorder, the other should also develop it if there is a strong genetic link. Adoption studies can also help to rule out developmental factors. If a birth parent of a child that has the disorder and the child gets it, even though they were raised in a different home, it points to a genetic influence.
Studies can also indicate whether a disease or disorder relies on a single gene or multiple genes. No single gene has been discovered in bipolar disorder studies, and its likely that bipolar disorder is caused by polygenic contributions, which means that its caused by many small changes in a persons genes. However, studies do suggest a major genetic contribution to your risk of developing bipolar disorder.
What Is The Main Cause Of Bipolar Disorder
Bi- polar disorder is a mental illness that causes a person to have multiple episodes of depression along with extreme and intense levels of anxiety. There is still no clear cause of bipolar disorder and its still unclear whether its a matter of nature or nurture. There are two different types of bipolar disorder which are called as Bipolar 1 and Bipolar 2. In Bipolar 1 the person experiences extreme mood swings and can also have manic episodes which are not present in case of Bipolar 2. Causes of bipolar disorder can include both external and internal triggers. External triggers include stress and pressure whereas internal triggers include the serotonin levels in the brain. Bipolar disorder is treatable and one can lead a healthy life if he is under proper treatment with the help of a psychiatrist and/or a psychologist..