How the Brain Works When It Is Manic or Depressive

Bipolar Definition

The brain, as far as many are concerned, is a huge mystery. This is part of the reason why mental illness is so hard to treat. The chemistry in the brain is already altered before medicines are introduced.

Bipolar disorder I is a mood disorder and a mental illness where a person fluctuates between the extreme highs of euphoria and the darkest depths of depression. Chemicals in the brain change during these moods. Bipolar I is a relatively common mental illness diagnosis and may begin in the teen years but usually onsets fully during the mid-20s.

Brain in Mania

Larger than normal amygdala with an increase in function has been found in people with bipolar disorder when compared to the percentage of people who have never suffered a mental illness or mood disorder. Those diagnosed with bipolar disorder have overactive left amygdalas and a diminished bilateral activity in the lateral orbitofrontal cortex. The orbitofrontal cortex is a region of the brain directly behind the forehead responsible for thought processing and decision making. This change in the brain explains the reckless behavior patients with bipolar disorder can take on during mania. The lack of foresight because of a diminished orbitofrontal cortex is what makes the patient act out and become unpredictable.

Brain in Depression

In an article by Jim Dryden concerning depressive episodes, Dryden says that each depressive state can damage neurons in the brain, making full recovery harder for the bipolar patient. Dryden goes on to assert that after each time a person suffers depression, the hippocampus, a structure in the brain that regulates learning and memory and is part of the limbic system in the brain, actually shrinks. He found that the more depressed an individual had been determines how small his hippocampus is.

Shared States

The neurotrophin-3, also known as the NT-3 neurotrophin, is overly active in both mania and depressive states in bipolar victims. Researchers are unable to link this overactivity to any particular function, but the signals that NT-3 creates somehow play a role in bipolar disorder, proving that the disorder is a true chemical change and not just made of emotional symptoms. Furthermore, CAT-scans verify the chemical changes in the brain during a manic and depressive state.

Brain and Mood Disorders

According to the Psycheducation website, during mood disorders, the brain does not only juggle unmanageable emotions and sensations but also shifts some of its usual functions. Older research focused on changing chemicals in the brain, but now theories are supporting the plausibility that instead of only the inside of the brain changing, the outside changes as well. It is also suggested that the frontal lobe of the brain shrinks as well in people with mood disorders like bipolar disorder. The frontal lobe controls emotional responses, as well as concentration and attention focusing. Thankfully, new evidence on the disorder suggests that treatment can actually reverse this shrinking, and the hippocampus becomes larger again over time with treatment.

Resources

• Psycheducation