Bipolar disorder can impact everyday life and relationships, but it may also imprint a pattern of effects on the brain.

Researchers are still exploring the relationship between the visible impacts of bipolar disorder, such as mood episodes, and the unseen impacts such as how it changes the brain.

Once known as manic depression, bipolar disorder involves changes in mood that can include the highs of mania or hypomania and the lows of depression.

About 1 in 100 adults live with bipolar disorder. According to the Diagnostic and Statistical Manual of Mental Disorders 5th edition, text revision (DSM-5-TR), three types exist:

  • Bipolar I disorder. Living with bipolar I disorder means you experience episodes of mania and sometimes depressive episodes as well.
  • Bipolar II disorder. This diagnosis involves at least one episode of depression and one episode of hypomania, a less severe form of mania.
  • Cyclothymic disorder. Also called cyclothymia or bipolar III disorder, this type involves episodes of depression and hypomania for a period of at least 2 years, but these episodes aren’t severe enough to meet the DSM-5-TR criteria for bipolar I or bipolar II disorder.

Learning more about bipolar disorder’s impacts on the mind could increase our understanding of how better to support people with bipolar disorder and improve treatment options going forward.

Bipolar disorder impacts various parts of the brain, including its gray matter and specific structures like the hippocampus.

Less gray matter

In your brain, gray matter forms the outermost layer and is responsible for many functions that make it possible to get through daily life, including:

  • processing sensory information
  • impulse control
  • movement and reflexes
  • storing memories

Bipolar disorder is linked to lower volumes of gray matter:

  • A 2020 study connected reduced gray matter in the brains of people with bipolar disorder to higher levels of inflammation.
  • A 2018 review of literature found lower amounts of gray matter in specific regions of the brains of people with bipolar disorder — the prefrontal cortex and temporal cortex, which are responsible for planning and storing memories.

A 2015 study also suggests that bipolar disorder could cause thinning in the frontal and temporal regions of the brain.

Smaller hippocampus

A 2016 study linked bipolar disorder to shrinking of the hippocampus, a part of the brain that supports:

The study didn’t find any big differences in hippocampal size between people with bipolar I and bipolar II disorder. It did find that when compared with the control group, people with bipolar I disorder had much smaller hippocampi.

Neurotransmitter imbalances

A 2016 review of literature connects bipolar disorder to imbalances in brain chemicals called neurotransmitters, especially serotonin or norepinephrine. It suggests that these imbalances could be responsible for the depression and mania that come with bipolar disorder.

Just because bipolar disorder impacts specific areas of the brain, it doesn’t automatically mean the functions of those regions will be impaired in the ways you’d expect — the brain is an extremely complex system, after all.

Still, researchers can speculate about how these changes could impact your thoughts and behaviors, painting a clearer picture of how bipolar disorder impacts day-to-day life.

A 2019 study found that older adults with bipolar disorder and reduced brain gray matter had:

  • reduced impulse control
  • more trouble with abstraction, meaning it could be harder for them to learn and form judgments

In addition, reduced gray matter and a smaller hippocampus could cause bipolar disorder symptoms including:

  • difficulty processing emotions
  • slower information processing
  • trouble with social cognition, or navigating the nuts and bolts of socializing

These impacts could come with challenges in aspects of day-to-day life like:

  • maintaining communication in relationships
  • navigating conflict
  • keeping sustained focus at work

Brain scans can’t diagnose bipolar disorder, but imaging techniques are sometimes used to reveal how bipolar disorder impacts the brain, according to a 2017 review.

When it comes to diagnosing bipolar disorder, a mental health professional will usually ask you some questions to determine whether that diagnosis applies to you.

A brain scan might be used to rule out other detectable conditions like tumors that can cause similar symptoms in some cases.

With the support of a mental health professional, you can use medications to lessen bipolar disorder’s impacts on your brain. Common medications include:

  • Mood stabilizers such as lithium: Research from 2016 found that people who take lithium for bipolar disorder have more cortical thickness than those who don’t take it, meaning it could help minimize the impacts of bipolar disorder.
  • Antipsychotic medications: A 2016 study found that antipsychotic medications had less ability to reverse or prevent brain changes caused by bipolar disorder than lithium. While researchers are still uncovering how antipsychotic medications work on bipolar disorder, they tend to help people manage symptoms related to mania.
  • Antidepressants. A 2015 review suggests that antidepressants reduced the size of the amygdala, responsible for emotional processes such as fear response in people with bipolar disorder.

Meanwhile, a 2021 study suggests that a form of mindfulness-based cognitive therapy (MBCT) could be a promising treatment for people with bipolar disorder.

The study highlights how the type of meditation used in MBCT could increase cortical thickness and gray matter volume, supporting brain function.

If it feels like bipolar disorder’s impacts are beyond your control, it could help to remember that many of the connections between brain differences and their associated behaviors aren’t solidified. And, while far from “cures,” coping strategies can help you manage its effects.

Some coping tips include:

Here’s a more in-depth look at how to cope with bipolar disorder.

Bipolar disorder can change specific areas of the brain, including its gray matter and hippocampus. Researchers have connected these changes to specific symptoms such as impulsivity, but the connection still isn’t clear-cut.

Medications such as lithium can help reduce some of the impacts bipolar disorder may have on the brain, especially stopping the shrinking of gray matter.

If you want to learn more about how medication and bipolar disorder may impact your brain, it could help to talk with a mental health professional who can help you decide which treatment approach or medication is right for you.