Bipolar disorder (BD) is a brain disorder that results in significant and severe changes in mood, activity, and energy levels, and ability to carry out the routine tasks of daily living. It is also considered one of the most heritable mental health conditions. New research led by scientists at the Broad Institute of MIT and Harvard University has pinpointed a specific gene as a strong risk factor for bipolar disorder and schizophrenia for the first time.
Unlike previous genetic links to the disorder, this new gene was found to have a significant effect on bipolar disorder risk. Scientists are hopeful that this discovery will help them develop new treatments for this complex mental health condition.
Having a bipolar disorder genetic risk factor, however, does not mean one will develop the condition. There are many other risk factors that play a strong role in its development.
New research led by scientists at the Broad Institute of MIT and Harvard University has pinpointed a specific gene as a strong risk factor for bipolar disorder and schizophrenia for the first time.
Here’s a closer look at bipolar disorder and its genetic underpinnings.
ABOUT BIPOLAR DISORDER
Bipolar disorder (BD), formerly called manic-depressive illness, is characterized by dramatic shifts in mood states and energy levels. However, these shifts are not the normal ups and downs that most people experience. They are more akin to intense emotional states or mood episodes that occur over a distinct period of time—sometimes days or weeks.
BD’s mood states are either manic/hypomanic (extreme happiness) or depressive (sad or low mood) and shift in a cyclical pattern, which creates a wide range of symptoms. Yet, people with bipolar disorder commonly have periods of neutral mood too.
Manic states can be intensely happy or highly agitated and typically involve a decreased need for sleep, grandiose ideas, or racing thoughts. Depressive states include low mood, loss of interest in activities once found pleasurable, and sometimes, suicidal thoughts (see a more comprehensive list of signs of manic/depressive episodes below).
When left untreated, bipolar disorder can greatly impact one’s quality of life. It can cause major problems such as:
- Self-esteem issues
- Poor performance in school
- Job performance issues
- Relationship troubles
- Substance abuse
- Hospitalization (39%, the highest rate of all mental health disorders)
- Shorter life expectancy (more than 9 years)
- Increased risk of suicide (15x greater than the general population)
Bipolar disorder is a serious mental health condition, ranking sixth on the list of the world’s leading causes of disability, according to the World Economic Forum.
Close to 6 million U.S. adults are affected by bipolar disorder, but it can affect children and adolescents too. The disorder typically begins in young adulthood (late teens to mid-20s), but it can start earlier in childhood or in mid-life as well.
WHAT CAUSES BIPOLAR DISORDER?
There is no exact cause of bipolar disorder, but experts have identified several risk factors for the condition, including heritable risk factors.
You may wonder, is bipolar disorder genetic? Indeed, it is—in part. Having one or more family members with bipolar disorder is a key risk factor and there have been genetic links to BD discovered in recent years, which are discussed below.
That said, there are other strong, non-genetic determinants in the development of BD. A history of emotional trauma, high stress, substance abuse, and changes in the structure and function of the brain can all play a role in BD.
Additionally, any of the following can factor into the development of BD, according to research:
- Medical issues
- Mental health disorders
- Traumatic brain injury
- Poor sleep
BIPOLAR DISORDER GENETIC RISK FACTORS
Twin, family, and adoption studies suggest that bipolar disorder has a significant hereditary component. About 15 years ago, researchers found that individuals with a first-degree relative (parent, sibling, or child) with bipolar disorder had a 7 times greater risk of developing the condition than the general population.
Indeed, a study involving twins found that the estimated heritability of bipolar disorder is more than 70% without shared family environmental effects.
Around the same time, researchers identified 2 genes—ANK3 and CACNA1—associated with bipolar disorder. Since problems with calcium signaling are associated with BD and these two genes contribute to the regulation of calcium, it was believed that they may play a role. However, it is still unclear, according to research.
More recently, a study published in the American Journal of Medical Genetics found a number of genetic variations linked to the condition. And just last year, in the research mentioned earlier, scientists identified the first strong genetic link to bipolar disorder, called AKAP11.
Still, the discovery of AKAP11 does not reveal too much about genetic risk for the general public. Its greater value may be what it reveals about the roots of BD. Researchers believe this gene may provide clues as to lithium’s effects on the body and open up the discovery of new therapeutic targets.
Lithium is one of the most widely used medications for the treatment of BD, although it comes with some undesirable side effects and safety concerns.
Though this evidence for genetic risk factors is strong, mental health experts have noted that in clinical practice, a positive family history of bipolar disorder is actually not very common. Of course, this underscores the influence of non-genetic factors in the development of BD.
SIGNS AND SYMPTOMS OF BIPOLAR DISORDER
If you suspect you or a loved one may have bipolar disorder, here are more detailed lists of symptoms for manic and depressive episodes.
Signs of a Manic Episode
- Unusually elevated mood
- Inflated self-esteem
- Less need for sleep
- An influx of goal-oriented activity
- Difficulty turning off the mind
- Lack of good judgment, which results in risk-taking behavior
- Grand ideas and plans
- Talking more or faster
- Unusually increased appetite
- Social behavior that’s inappropriate
- Aggression or irritability
- Hallucinations or delusions
- Racing thoughts
- Compulsive sexual or hyper-religious behavior
Signs of Depressive Episodes
- Sad or negative mood that persists
- Loss of interest in activities that normally bring pleasure
- Changes to sleep, getting either too much or too little, or waking too early
- Feeling “slowed down,” fatigued, decreased energy
- Trouble concentrating
- Feeling guilty, worthless, helpless, and hopeless
- Morbid or suicidal thoughts, or suicide attempts
Of course, like so many mental health disorders, BD is not a simple condition or just one thing. Experts recognize at least 4 types of bipolar disorder, including the following:
- Bipolar I disorder
- Bipolar II disorder
- Cyclothymic disorder
- Bipolar disorder not otherwise specified (NOS)
The distinction between each type has to do with the severity of symptoms. For instance, bipolar 1 disorder is viewed as the most severe form of the disorder.
BIPOLAR DISORDER IS HIGHLY TREATABLE
If you recognize the signs of bipolar disorder in yourself or someone you love, reach out to a qualified mental health professional. There’s great hope with BD. The National Institute of Mental Health (NAMI) reports that with proper treatment, 70% to 85% of patients recover.
This article was written by Amen Clinics.