The idea behind the Serotonin Diet, and Potatoes not Prozac, is that eating carbs changes the proportion of tryptophan in the blood trelative to other aminos and so more trp gets into the brain hence serotonin is raised. Wurtmabn's research has shown that a proteiny meal without carbs means proportionally less trp in the blood, whereas carbs with the meal keep the trp ration higher. Eating carbs on their own triggers an insulin release which causes the preferred aminos for muscle to be taken up, leaving trp behind to preferentially get across the blood-brain barrier, hence raising serotonin. It's not about eating high carb, in fact it is vital to eat the carb 2-4 hrs after a good protein meal, otherwise the aminos won't be there in the first place. I don't have the links handy but if you look up Judith Wurtman's research there's lots of good stuff out there.
The question for me is, if paleo is our natural diet why do so many of us have this issue? I wonder if epigenetics are a factor. If our grandparents and parents etc grew up eating high carb, then maybe our gene expression has been adjusted for that to avpid our serotonin level being unnaturally high, or to downregulate receptors to adjust for high serotonin. Then we were fed high carb from a few weeks after birth (unless you were a very lucky baby). Can it be reversed? I have been paleo for a year now and not been able to do it but I am still hoping I can tweak things and find a way to stick to low starch and sugar (I need to now anyway to treat ankylosing spondylitis), and maybe if I can do it longer term my body and brain will adjust and the low carb induced depression will lift. In Potatoes not Prozac, she talks about how endorphin receptors are down regulated in responses to endorphin spiking from eating sugar, so when you go off sugar you feel flat for about 6 months until you readjust and upregulate. Maybe it can work the same with serotonin.
I was thinking of trying timed fruit or honey once I've done intro, so this thread is useful. I am just hoping I can stick to it, now I know that the joint pain is a potentially serious condition maybe that'll give me a kick, but still, I need to at least be able to ameliorate cravings and avoid the depth of depression I went into whilst on LC paleo.