More about caffeine

Hi guys,

So I was reading more in 'little sugar addicts' about how excess caffeine can reduce serotonin, is this true?

Does this mean that caffeine makes our bodies produce less, or rather it depletes what we already have in store? Also, I wasn't clear on this part but the book mentions a link with serotonin and impulse control. Now I am absolute CRAP with impulse control. I can make decisions on a whim, change my mind faster than the speed of light.

I get confused because..I always thought that sugar DID help with serotonin production,and serotonin does lots of other things too I think...like help us to feel happier, more at peace?

So mainly, I am trying to understand...is sugar the cause for having problems with decision making, clear thinking and impulse control? And is sugar also the cause for low serotonin, which CAUSES this difficulty with impulse regulation?