June 22, 2007

New Gene Identification That Provides Clues to The Differences Between Schizophrenia and Bipolar Disorder

A new article published in this month's issue of the Proceedings of the National Academy of Sciences outlines gene variations found in people suffering from schizophrenia and bipolar disorder. The goal of this study was to determine more specifically the differences between these two psychiatric disorders. Finding differences in genes would hopefully lead the way to new, better, treatments. Currently many drugs created for one of these disorders is also used for the other; with often less than ideal results.

The study focused on genes responsible for regulating GABA. GABA is the brains universally inhibitory neurotransmitter. It is highly concentrated in the hippocampus of the brain, which is responsible for learning, memory, and spatial processing. Previous studies have found deficits in GABA function specifically in the hippocampus portion of the brain in those suffering from either schizophrenia or bipolar disorder.

The study included only 21 brains, 7 in the schizophrenia group, 7 in the bipolar group, and 7 control brains. They found 25 different genes possibly involved in the regulation, GAD67, a GABA marker in the hippocampus. Bipolar patients had 10 of the genes, schizophrenia patients had 12, and the control group showed none.

"We cannot say for sure that these are the genes that cause the illnesses, but it seems likely that in some way they may be related to susceptibility to one or the other of the disorders and that is important,'' said Francine M. Benes, MD, PhD, director of the McLean Hospital Program in Structural and Molecular Neuroscience, and lead author of the paper.

"We would like to be more specific,'' said Benes, who is also the William P. and Henry B. Test Professor in Psychiatry in the field of Neuroscience at Harvard Medical School and a member of the prestigious Institute of Medicine of the National Academy of Science. "What we need from the standpoint of clinical care are more specific forms of therapy. In order to define more specific types of drug treatment, we need to understand these illnesses at this level of cells and molecules. The findings of this paper bring us closer to that.''

Read full article:

Regulation of the GABA cell phenotype in hippocampus of schizophrenics and bipolars. By: Francine Benes, Benjamin Lim, David Matzilevich, John Walsh, Sivan Subburaju, and Martin Minns. Proceedings of the National Academy of Sciences, Vol. 104, No. 24. June 6th 2007.

Identification of Genes Provides New Clues into the Causes of Schizophrenia and Bipolar Disorder

Expert Interview with Francine Benes on GABA cells and Schizophrenia and Bipolar Disorder


Perhaps this abstract will help others understand this better, as it helped me:

The same genes are actually being expressed differently, which results in the variation of disorders seen.

"genes were differentially expressed in subjects with BD, including a number of genes in the mitochondrial electron transport chain (ETC), phosphatidylinositol-signalling system and glycolysis/ gluconeogenesis. Eight genes coding for the components of the mitochondrial ETC were identified along with 15 others related to mitochondrial function."

What I find fascinating about that is that the mitochondrial DNA is completely separate from what we consider to be the "human genome" - the DNA which we normally think of as our DNA.

And that they found multiple genes involved in both schizophrenia and bipolar being EXPRESSED differently AND involving mitochondrial transport chains highlights to me the enormous complexity of the illnesses we call "schizophrenia" and "schizoaffective disorder".

I will be greatly interested in future findings in this area.

Posted by: Naomi at June 24, 2007 08:07 AM

I've lived with a family member who showed short stretches of normalcy...and longer stretches of paranoia,suspicion,deep sadness, and anger; close family members have paid emotionally for this relatives illness. I am very intrested in learning more about this disorder.

Posted by: Dafina at September 18, 2007 07:35 AM

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