Friday, June 26, 2009
Above is an illustration of the brain showing the circuitry that is attracting the attention of researchers across just about all fields of mental illness. This PowerPoint slide comes from a talk given at this morning's session at the Eighth International Bipolar Conference in Pittsburgh by Hilary Blumberg of Yale.
What you are looking at is two-way traffic between the reactive/arousal amygdala and the thinking/modulating cortical areas. Abnormalities in these circuits has been implicated in all manner of mental illnesses. Essentially, when things go wrong, the emotional amygdala is shouting too loud and the rational cortical areas fail to reassert control.
Below are two fMRI images of a bipolar brain in action, from a study currently in press. These slides were presented at the same session by Mary Phillips of the University of Pittsburgh. What we are observing are top down images of the two-way traffic between the amygdala and the orbitomedial prefrontal cortex. On the left side, in a normal reaction, you see evidence of heavy and direct traffic while the smaller arrows to the right indicate lighter traffic.
In the bottom image, the denser arrow to the right notes an over-reaction, which shows up in bipolar subjects, but is not in evidence in healthy control subjects or in unipolar depressed individuals.
In yesterday's blog, we were looking at brain dysfunction on the "cellular level". Here, we are viewing the things that can go wrong on the "systems level". Using brain imaging, Dr Phillips has been able to distinguish between unipolar and bipolar. Dialing in the research further promises to further sharpen our diagnostic capabilities.
I asked Dr Phillips about this. On previous blogs, I showed brain scans of similar breakdowns in the circuitry between the back and front areas of the brain in patients with borderline personality disorder, a very similar picture to what you are looking at now. It's only a matter of time before we can use brain scans to separate out borderline from bipolar.
These are exciting times. John McManamy, live from Pittsburgh ...