How Does Bipolar Disorder Affect The Brain?

Reduced Gray Matter in the Brain

First, let’s talk about how bipolar disorder affects gray brain matter. The central nervous system is made up of two different kinds of tissue: gray matter and white matter. The gray matter in the brain enables us to control movement, memory, and emotions. It mainly serves to process information in the brain. Structures, like axons, carry signals generated by our sensory organs and include touch, smell, sight, hearing, and taste. The gray matter sends signals to nerve cells in the central nervous system where nerve synapses, which are spaces between neurons, produce a response.

One study led by the USC Stevens Neuroimaging and Informatics Institute at the Keck School of Medicine of USC: ENIGMA (Enhancing Neuro Imaging Genetics Through Meta-Analysis) on bipolar disorder brain function showed thinning gray matter in the brains of patients with bipolar disorder. The greatest of these deficiencies were found specifically in the frontal and temporal regions of the brain. Additionally, some patients with bipolar disorder in the study also showed greater discrepancies in gray brain matter.² When your brain matter decreases, you may experience symptoms like:

• Decreased impulse control
• Decreased control over your senses
• Difficulties regulating your reflexes or reaction time
• Difficulty with motor skills like balancing, drawing, speaking, and writing

These symptoms could explain why manic episodes often seem impulsive, careless, or reckless. Having less gray matter in the brain can also cause sluggishness and frustration, as well as trouble performing simple tasks when you are experiencing a depressed bipolar episode.

Shrinking of the Hippocampus

Bipolar brain function is also associated with the hippocampus. The hippocampus plays a role in learning, consolidating, and memory retrieval. It’s also involved in verbal memory functions, stress responses, emotions, goal-directed activity, and sensorimotor integration. A recent study found that patients with bipolar disorder showed reductions in the hippocampus compared to people without mood disorders.3 When this occurs, memory is severely impacted. The right side of the hippocampus helps you associate places with specific memories, while the left side regulates verbal and visual memory. This region of the brain helps you regulate your emotional responses.

When the hippocampus shrinks, certain symptoms can occur, including:

• Depression, which can lead to depressive episodes
• Memory problems, which can lead to paranoia
• Frustration
• Irritability
• Unregulated emotional responses, which can contribute to shifts in mood
• Confusion

Severe shifts in mood are a common sign of bipolar disorder. People who suffer from this disorder should seek out professional mental health treatment to avoid self-destructive coping methods – such as substance abuse – and to learn how to manage their symptoms.

If you’re still wondering “how does bipolar disorder affect the brain”, to sum it all up, the effects of bipolar disorder on the brain include:

• Impaired attention, memory, and problem-solving
• Impaired ability to store memories, or associate certain places with specific memories
• Difficulty regulating your emotions
• Frustration, paranoia, and irritability, all of which can lead to manic or depressed episodes
• Confusion
• Learning disabilities and speech impairment
• Reduce verbal learning, declarative, and spatial working memory
• Sleep problems
• Risk-taking behaviors