Bipolar Disorder

What is the difference between bipolar disorder and depression? Are they related? Are their similarities in their biological basis?  What makes someone switch from manic to depressive states? Does the brain of a bipolar patient that is going through a depressed episode exhibit the same patterns as a person diagnosed with unipolar depression?  These are just some of the questions that I have about the relationship between depression and bipolar disorder.  Sitting in class I could not help but think that there must be similarities between these two disorders since bipolar disorder is often marked by long periods of depression.  If they are exhibiting similar symptoms are their biological symptoms the same?

In my search for answers to this question I realized that as little is known about depression, even less seems to be known about bipolar disorder.  I found many articles explaining that behaviorally there is a difference between depression and bipolar disorder, but they weren’t recognized as separate disorders until 1966! The articles that initially discussed the differences cited differences in genetics, gender, clinical course, and premorbid personality.  All of these seem to be reasonable support for defining depression and bipolar as different disorders, but what about the biological component?

The article I read, “Are Depression and Bipolar Disorder the Same Illness” reviewed work done by Frazier et al. who found several interesting biological components to this disorder (but the article I read didn’t cite it, so I can’t find it anywhere!).  But his research found differences in the limbic systems of prepubescent children with bipolar.  Frazier also found that the hippocampus volume decreased in children with bipolar disorder, but this was not found in adults with bipolar disorder.  This brings up two questions: Is bipolar in childhood fundamentally different from adult bipolar disorder? And is the decrease in hippocampal volume of bipolar patients similar to the same symptom found in depressed patients?  In the research I did it felt like I came up with more questions than I got answers.  There is still so much to understand when it comes to Bipolar disorder!


6 thoughts on “Bipolar Disorder

  1. And… does child bipolar disorder look more like adult depression than it is like adult bipolar disorder? From the hippocampal volume decreases it seems like it! I wonder if the manic episodes are quite different from childhood to adulthood, and maybe that’s why bipolar disorder starts to look different in adulthood. I’m assuming it’s a gradual change, but I’d be interested to find out what ages the categories of children and adults encompassed (did they study late teens?) If they did, I would hypothesize that if they took the brains of young children and older adults with bipolar disorder, the differences might look even greater without the teen data in there.


  2. These results comparing the child and adult hippocampus seem very interesting to me and I wonder what the reasons may be for the same. As I think about it, it is possible that one of the reasons could be a difference in the degree of neuronal plasticity that is possible in the brain based on age. We know that plasticity within the brain decreases with increasing age. Do children suffering from Bipolar have smaller hippocampi because their brains are more plastic during this critical developmental period and so more sensitive/prone to change- negative or positive? At the same time I wonder the opposite which makes me think that because their brains are more plastic shouldn’t they also be more resilient and compensate for reduced volume in some way or the other? What did the article by Frazier discuss as possible reasons for this?


  3. I have always saw stronger connections between bipolar disorder and schizophrenia than bipolar disorder and depression. Perhaps I am biased because I worked with both schizophrenic and bipolar patients in the same facility, who were all paired there due to the similarities in their paranoid symptoms and their behaviors. However, I feel as thought the link to depression is more of an issue of comorbidity. People who are bipolar and manic would probably experience more depressed states because of the confusion of their mania. Just a thought.


  4. I finally found the article by Frazier et al. and found a few more interesting facts. Their study looked at youth (6-16 years of age) and found decreased volume in the hippocampus, but they also cited another study that found that adolescence showed this same decreased volume. It is only adults that don’t show this difference. Frazier et al. gave several explanations for this difference. They state that previous studies have suggested that there may be “abnormal neurodevelopment and remodeling of synapses in [the hippocampus]” of bipolar youth. They also talk about the abnormalities as a preexisting venerability and not a cause of bipolar disorder in youth. Finally he talks about the interaction of genetics and the environment as a possible “double hit” causing the differences found in youth.


  5. Great questions! some clues could be derived discovering what’s abnormal in the two disorders and what works to prevent/treat them. Going to the childhood syndromes for clues seems like a pretty murky endeavor. There is definitely mounting evidence that there is something different about a host of these disorders when they manifest in children or adolescents.


  6. Is this difference reflected in adults who developed bipolar disorder in childhood or is there a recovery in adults from childhood? This is the first I’ve heard about physical symptoms of a mental illness being different in children and adults. This is especially interesting for me because I am so interested in development in children.


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