Is bipolar inherited?

Bipolar disorder, formerly known as manic depression, is a mental health condition characterized by extreme shifts in mood and energy levels. People with bipolar experience periods of mania (elevated moods, increased energy and activity) and periods of depression (low mood, loss of interest, low energy).

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Is bipolar genetic?

Research shows there is a genetic component to bipolar disorder. If one identical twin has bipolar disorder, the other twin has an 80% chance of developing it as well. For non-identical twins, if one twin has bipolar, the other has a 15-25% chance of developing it.

Studies of families where bipolar disorder is present show that a person who has a first-degree relative with bipolar (such as a parent or sibling) has an increased risk of developing the condition themselves. The risk is higher if multiple relatives have the disorder.

However, genetics alone do not determine whether someone will develop bipolar. Most people with a family history of bipolar will not develop the condition. Other factors like environment, life experiences and brain chemistry also play a role.

Genes linked to bipolar

Researchers have identified several genes that may increase susceptibility to bipolar disorder when combined with other factors. These include:

ANK3
CACNA1C
ODZ4

NCAN
TRANK1

Studies show these genes regulate important processes in the brain like neuron excitability, plasticity and resilience. Variants in these genes may lead to dysfunction in the circuits that manage mood, thinking and behavior.

However, each of these genes only confers a small increase in bipolar risk. There are likely many more genes involved, each making a small contribution to overall susceptibility.

How bipolar disorder is inherited

Bipolar disorder does not follow typical Mendelian inheritance where a single gene variant is passed down and directly causes the disorder. Instead, it is what is called a “complex” genetic disorder:

Multiple genes are involved, each contributing a small amount to overall risk.

Environmental factors and experiences also play a role by influencing how these genes are expressed.
Having certain gene variants does not mean someone will definitely develop bipolar. Many other factors come into play.

This helps explain why bipolar disorder can seem to “skip” generations or have different manifestations in members of the same family. The interplay between genetic susceptibility and experience is complex.

Other biological factors

In addition to genes, other biological factors are often abnormal in people with bipolar disorder:

Brain structure: Structural changes in areas that regulate mood and thinking have been observed.
Neurotransmitters: Dysregulation in neurotransmitters like serotonin, dopamine and glutamate.

Hormones: Abnormalities in cortisol, thyroid and sex hormones.
Circadian rhythms: Disruption of 24-hour bodily cycles linked to sleep/wake and hormonal patterns.

It is not clear yet whether these biological abnormalities are the result of genetic effects, downstream impacts of the disorder, or a combination. But research shows they play an interactive role with genes in bipolar’s development and expression.

Environmental and lifestyle factors

In addition to genetic susceptibility, environmental and lifestyle factors can influence whether someone develops bipolar disorder:

Childhood trauma such as abuse, neglect, loss of a parent, etc.
High stress or emotionally traumatic events

Drug or alcohol abuse
Periods of poor sleep or sleep disruption
Use of certain medications like antidepressants, steroids or stimulants

Severe postpartum stress or psychiatric illness after giving birth

These environmental factors may interact with genetic vulnerability by influencing brain chemistry and function in ways that affect mood stability. However, positive environmental factors like medication compliance, therapy, stable routines and social support can improve outcomes.

Is bipolar more common in creative people?

There is a widespread perception that bipolar disorder is more common in creative professions like art, writing and music. However, research findings on this have been mixed:

Some studies have found a modestly increased rate of bipolar spectrum disorders among artists, musicians and writers compared to the general population.
Other studies have found no difference in bipolar rates between creative and non-creative professions.
Creative thinking abilities do not necessarily appear enhanced in people with bipolar compared to healthy controls.

It is unclear if any relationship between bipolar and creativity is due to biology, temperament, cognitive style, or aspects of these environments. Many famous creators had mental health conditions, but that does not mean mental illness itself confers creativity.

Can you develop bipolar later in life?

Bipolar disorder most often develops in late adolescence or early adulthood, with a median age of onset around 25 years old. However, it can also first appear later in life.

Around 10% of bipolar cases have an onset after age 50. Some possible reasons for late onset include:

The disorder was previously misdiagnosed or overlooked.
A later-life traumatic event or stressor triggered the onset.
It emerged due to age-related biological changes in the brain.

Late-onset bipolar cases may have some differences in symptoms, course and family history compared to early onset. However, overall treatment approach is similar regardless of when bipolar first appears.

Can medications or drugs cause bipolar disorder?

Substance use does not directly cause bipolar disorder in someone with no biological vulnerability. However, certain substances may trigger onset or affect the course of existing bipolar:

Stimulants like cocaine, amphetamines, ADHD medications can trigger mania and psychosis in vulnerable individuals.

Antidepressants may trigger mania or rapid cycling, especially in undiagnosed bipolar.
Steroids such as corticosteroids may cause mania, as can over-the-counter nasal sprays.
Drug withdrawal may precipitate depressive or manic episodes.

In addition, substance abuse can worsen bipolar progression and treatment outcomes. Drugs and alcohol are common ways those with bipolar try to self-medicate their symptoms.

Are there links between bipolar disorder and anxiety or addiction?

Bipolar disorder has high rates of co-occurring conditions. These include:

Anxiety disorders: Up to 75% of those with bipolar have an anxiety disorder like panic disorder, OCD or PTSD.

Substance abuse: Around 60% have a history of drug or alcohol abuse or dependence.
Eating disorders: Rates of bulimia nervosa and binge eating disorder are 2-3 times higher in bipolar.

It is not fully clear how these conditions interrelate. Shared genetic risks, brain changes and environmental factors likely all contribute. Having a co-occurring disorder can make bipolar more difficult to treat.

Can you be bipolar without a family history?

It is possible to have bipolar disorder without a family history, but this is less common. Around 80% of people with bipolar have some family history of a mood disorder. However, there are several reasons one may not have a family history:

The family history is unknown or obscured, as can happen with adoption.
The person has a de novo (new) genetic mutation that was not inherited.

Environmental factors are playing a larger causative role.
Other biological factors beyond genetics are involved.

Lack of family history does not rule out a bipolar diagnosis. The doctor will ensure all diagnostic criteria are met regardless of whether it runs in the family.

Can you have bipolar with mild symptoms?

Bipolar disorder occurs on a spectrum, with milder versions classified as:

Cyclothymic disorder: Milder mood fluctuations that do not meet full criteria for hypomania or depression.
Bipolar II: Periods of hypomania (less severe than full mania) alternating with depression.

Even the classic “bipolar I” with severe mania has periods between episodes where function is relatively normal. Additionally, effective treatment can minimize symptoms.

So while some have very impaired functioning from bipolar, it is possible in milder cases or with good treatment response to have relatively normal moods, relationships and abilities most of the time.

Is bipolar becoming more common?

Rates of diagnosed bipolar disorder do seem to be increasing over recent decades:

Lifetime prevalence rose from around 1% in the 1970s to over 4% in more recent surveys.
Rates in youth increased about 40% between the mid-1990s and mid-2000s.

However, it is unclear how much of this rise is real versus increased awareness and detection:

Bipolar remains underdiagnosed today, with nearly 60% of cases missed initially.
Increased education and awareness may be identifying previously missed cases.
Expanded diagnostic criteria may be classifying more people as bipolar.

Changes in risk factors like drug use may play a role.

While rates have certainly risen, true increase in illness prevalence may be lower than statistics suggest. Better understanding is still needed.

Can you have bipolar symptoms without the full disorder?

It is possible to experience bipolar-like symptoms without meeting criteria for the full bipolar diagnosis. Examples include:

Mood swings due to hormonal changes, medications or stress.
Brief depressive reaction to a major loss or life event.
Hypomania triggered by drug or alcohol use.

Depressive episode due to a medical condition or its treatment.

Symptoms may resemble bipolar but have a clearly identifiable cause outside typical bipolar mechanisms. They may not recur over time like discrete bipolar episodes.

However, significant or persistent symptoms should be evaluated for a possible clinical disorder. Accurate diagnosis leads to proper treatment.

Does bipolar worsen with age?

The course of bipolar disorder varies between individuals. But research suggests:

Episode frequency remains stable or decreases slightly in mid to later life.
Mania symptoms tend to lessen with age, while depression remains steady or worsens.

Functional recovery between episodes is slower later in life.
Cognitive function may decline faster compared to non-bipolar individuals.

So while mania often improves, depression and cognitive effects may become more pronounced in older adults. Careful management of physical and mental health is important.

Can bipolar develop after having a baby?

Women are at very high risk of a first episode of postpartum mood illness after giving birth. This includes:

Postpartum depression – depressed mood, sadness, crying spells.
Postpartum psychosis – delirium, hallucinations, delusions.

Postpartum mania – euphoria, high energy, racing thoughts.

While postpartum mood disturbances are often temporary, woman have a 20-30x increased risk of being hospitalized with mania or psychosis in the first month after delivery.

For those predisposed to bipolar disorder, the hormonal changes of childbirth may trigger a first bipolar episode. However, postpartum mood illness on its own does not mean a woman necessarily has bipolar disorder.

Conclusion

Bipolar disorder arises from a complex interplay between genetic vulnerabilities, brain changes and environmental experiences. While genetics play a role, it is not strictly inherited in a predictable pattern.

Risk is increased with a family history of bipolar, and certain genes have been implicated. However, no genes definitively cause or predict the disorder on their own. Environment and lifestyle also influence its development and course.

Ongoing research aims for better understanding of bipolar’s biological basis and patterns of inheritance. This can improve diagnosis and lead to more personalized, effective treatments.