According to a recent article by Nathan Collins at Pacific Standard, new studies are suggesting that significant structural differences exist between the brains of not only bipolar and “normal” brains, but between Type II and Type II bipolar brains.

Around 2.5% of the United States population are bipolar disorder sufferers, which is equal to about 6 million Americans. A person with the Type I disorder is defined as an individual who has had at least one manic episode, which is a period of abnormally elevated mood, energy, as well as abnormal behavior, at least one time in their life. Some individuals experience this disorder on a more consistent rate: they experience cycles (much more often than one time in their life) between depression and mania; also known as a cycle between great sadness and great happiness and/or irritability. There are many symptoms of Bipolar 1 Disorder during the period of mania, some of which include switching quickly from one topic to another; rapid, loud speech; increased energy and a decreased need for sleep; increased self-image; excessive spending; hyper-sexuality; and substance abuse. Symptoms of depressive episodes include a depressed mood; loss of pleasure, energy, and activity; and feelings of guilt, worthlessness, and even suicide.


Type II Bipolar disorder is very similar to Type I in that the individual’s mood cycles between mania and depression. However, in these Type II individuals, the “manic” episodes never meet full blown mania. What these individuals experience is a term known as “hypomanic episodes”. Like Type I, an individual who is diagnosed with Type II has experiences at least one hypomanic episode in his or her life. However, also like Type I, some individuals may experience these episodes up to 4-5 times a year. The symptoms of Bipolar II include switching quickly from one topic to another; rapid, loud speech; and increased energy, with decreased need for sleep. Unlike Bipolar I, individuals with Bipolar II may even be pleasant to be around. In many cases, these individuals have been reported as happy, optimistic, caring, and “the life of the party”. The symptoms of depression for Bipolar I are very similar to Bipolar 2.

For a long time, researchers have been at a dead end when trying to analyze the causes of Bipolar disorder. However, with new and more developed technology, researchers have been able to study differences between Type I and II bipolar brains; a theory they have believed to be behind the cause of Bipolar disorder for a long time.  Dr. Jerome Maller and his team at Monash University in Australia decided to take a deeper look into the matter. Using standard MRI scans and a new technique called diffusion tensor imaging (which measures the amount of the brain’s white matter), they developed an experiment which included 16 Type II patients, 15 Type II patients, and 31 healthy control subjects. Their main focus was determining whether or not there were structural differences in gray matter, white matter, and cerebrospinal fluid.

The researchers found that there was not only small structural differences, but less TOTAL BRAIN VOLUME in patients with bipolar disorder. There was less gray and white matter and more cerebrospinal fluid volume in bipolar patients compared to healthy subjects. However, after controlling for total brain volume, the researchers found that Type II brains had practically the same sized brains as the controls’ brains. The DTI studies found that patients with Type I and Type II had reduced white matter relative to healthy brains. Even more interesting; those with Type II had even less white matter, particularly in the frontal and prefrontal cortex, than those with Type I; possibly eluding to the theory that Type II bipolar disorder is a “cognitive dysfunction”.

Researchers are no where near finished with studying these brain and bipolar disorder, but what they have done so far is a great start, thanks to new technology. Future improvements in their studies will include access to data on how long these patients have been diagnosed with bipolar disorder; how long they have actually had the disease; larger sample sizes, and additional information on factors such as medication, family history, and genetics.

On a side note from the article:

This author commonly referred to Bipolar patients as having a disorder. Dr. Rettinger often talks about how we immediately label those that seem different; such as individuals with Autism, ADHD, or Down Syndrome; as having a disorder and/or a disease. How can we call ourselves normal when there is no definition of what a normal human being really is? As the image states above, individuals that are considered bipolar often have symptoms of high levels of creativity and energy; and it is found in most geniuses. Now, I do not know how true that really is, but it really made me think and relate back to what Dr. Rettinger often says in class.