Dr Sara Pugh: "What's the real cause of bipolar disorder?"
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Dr Jack Kruse: "Maybe I can give it to you like this. I want you to think about all human mental illness as a bowling alley. The two gutters on either side, one is depression, that's the low dopamine state. Schizophrenia is the other gutter, that's the high dopamine state that's released chaotically.
"Bipolar disorder is in the middle but closer to schizophrenia. The reason for that is defects on the retinohypothalamic tract that go to the habenular nucleus, that then get relayed from the hypothalamus and the thalamus into the orbital frontal gyri, to affect the reward tracts. That's actively what happens. The single big effect is that tract is out of whack with the oscillations of the same tract that goes from the RPGs into the suprachiasmatic nucleus.
"To get bipolar disorder you have to have the hard tract (that I just gave you) plus you have to have the circadian mechanism completely broken. What people don't realize that the initial part from the retina into the hypothalamus is actually the same tract. Remember that the retinohypothalamic tract synapses in the SCN and the habenular nucleus. They're both the same; it means the gunshot is the same.
"But to get different diseases, what happens if one tract is out and the other one's not? OK? Or what happens if they're both out? That explains the difference. OK?
"With schizophrenia, it's the third tract, it's all those tracts that go from the thalamus that radiate up into the frontal lobes, they all have to be damaged. What you're basically seeing, I use the analogy in the podcast that it's almost like a train station. Which part of the train station is damaged on the line? You know that a line in the Underground in the UK has 20–30 stations. Well, what I'm saying to you is every mental disorder is damage to a different station along the tract from the eye (or the skin) all the way through.
"I haven't talked about the skin too much, because understanding from the eye is easier. But believe it or not, do I think there is an issue between the eye and the skin when you give it a mismatch, like just by wearing clothes you're much more likely to actually have a mental illness."
Dr Jack Kruse with Dr Sara Pugh @ 01:17:29–01:20:15 https://youtu.be/cy8cByk8H00&t=4649