How Does Bipolar Disorder Affect the Brain?

Family and friends say you’ve always been moody, but lately, you’ve noticed changes in your energy levels, and there have been moments when you can’t think coherently. Depending on how often this happens, you could be suffering from a mental health illness called bipolar disorder – and it may affect your brain.

What is Bipolar Disorder?

Bipolar disorder is a mental illness resulting in dramatic shifts in your mood, energy, and capacity to think clearly. It’s a condition that features high and low moods (mania and depression), which vary from regular ups and downs you might have.

It usually starts around the age of 25 but can also happen in teens and even in childhood. Men and women are equally affected, with about 2.8% of the U.S. diagnosed with bipolar disorder and almost 83% of those considered severe cases.

Symptoms of bipolar are both manic and depressive, characterized by:

• High emotions or a sense of elation.
• Low or empty moods and a sense of worry.
• Feeling like you’re wired.
• Restlessness.
• You feel like you can get by on little or no sleep or have sleep problems.
• You have issues with your appetite, characterized by weight loss or gain.
• You talk quickly or slowly.

Bipolar Disorder and the Brain

Bipolar disorder can affect the following areas of the brain:

• Hippocampus. According to the U.S. National Institutes of Health, the hippocampus is a multifaceted brain structure rooted deep in the temporal lobe. It plays a major role in how we learn and remember. It’s a pliable and exposed structure that many stimuli can harm. Research has proved that it also gets affected (its structure and function may change) if someone has been diagnosed with a range of neurological and psychiatric disorders, including bipolar disorder. Other studies have shown that bipolar disorder and other conditions may herald a loss of gray matter, particularly in the orbital and medial PFC, ventral striatum, and hippocampus.
• Amygdala. The amygdala is a collection of neurons located deep within the brain’s temporal lobe. The term itself is derived from Latin and means almond, partly because it resembles an almond. It’s often referred to singularly, but there are two – one in each cerebral hemisphere. It’s a part of the brain critical to emotions, emotional behavior, and motivation. One study indicates that the amygdala may demonstrate functional problems in someone with bipolar disorder, particularly as it relates to emotional memories and how that affects someone’s reactions.
• Ventral prefrontal cortex. The U.S. National Institute of Mental Health says that the ventromedial prefrontal cortex (VPC) plays a significant role in a range of social, cognitive, and affective functions which get disrupted in mental illness, including diagnosis of bipolar disorder. Highly interconnected with the amygdala, the VPC also plays a vital role in emotional regulation – again, a hallmark of people experiencing bipolar disorder. When the connections between the two are disrupted, someone with bipolar may be subjected to mood swings and emotional highs and lows.
• Bipolar disorder has also been shown to reduce the brain’s gray matter volume. Gray matter throughout the central nervous system gives someone greater control over emotions, memory, and movement. It makes up the brain’s outmost layer and has a pinkish-grey tone, hence gray matter. 

Bipolar disorder may also be driven by chemical imbalances, which influence your moods, help cells transmit messages back and forth, and regulate heart rate. The driving force behind all this activity are neurotransmitters, and it’s believed that three may play a role in how bipolar disorder develops in certain people: noradrenaline, serotonin, and dopamine. All three glutamates are unique, inducing mental and physical responses and functioning as neurotransmitters and hormones.

Diagnosis & Treatment

Diagnosing bipolar disorder relies on a medical examination. Your healthcare provider or clinician will:

• Perform a physical exam. Certain tests may be performed to see if there’s an underlying medical cause for your symptoms.
• Complete a psychiatric assessment to talk about thoughts, feelings, behavior patterns, and whether you or a family member has a history of mental illness.
• Ask you to fill out a mood chart to help track mood changes, duration, frequency, and possible triggers. This information can help inform the diagnosis and develop a treatment plan.
• Compare your symptoms with bipolar disorder criteria in the Diagnostic and Statistical Manual of Mental Disorders.

Successful treatment may involve different kinds of therapy, self-help, support groups, diet and lifestyle changes, medicine, or even ketamine therapy.