Is there some reason why caffeine (or other stimulants) produce mixed reactions?

Drinking a beverage with caffeine in it perks me up somewhat. I always have a coffee or two in the morning, and usually a cola at lunchtime to keep me from feeling drowsy during the afternoon. But my wife can’t drink any caffeine or she becomes a 33 1/3 played at 78 (remember vinyl, kids?). I mean, the woman simply can’t shut up.

My seven-year-old takes two sips of Mountain Dew and starts bouncing off the walls. Granted, he only weighs what a normal first grader weighs, but even if I chug a whole can of Dew, I’m perfectly capable of sitting still.

How much of this is acclimation and how much of it is the individual’s chemical makeup?

Caffeine has absolutely no effect on me–none at all.

However, not getting a steady supply invariably results in headaches.

I know I didn’t answer the OP, but my WAG is that when you drink a lot, you become sorta immune to the drug-like effects–but now you’re addicted, and your body wants it and goes thru withdrawal when it doesn’t get it.

Caffeine is one of those substances to which a body rapidly builds up a tolerance.

When you do the Dew, you also ingest lots and lots of sugar. That might help drive your young’un beserk.

Slightly off-topic, the SD Science Advisory Board gives the dope on caffeine products here.

According to this site, and many others, the old canard about sugar causing hyperactivity isn’t supported by science.

Sugar apparently is not as bad for children as popularly believed. A study reported in the New England Journal
of Medicine concludes that contrary to the belief of many parents… sugar does not turn their children into
hyperactive terrors. In fact… the researchers say their study suggests that sugar may even have a slight calming

 The researchers say that despite their findings... they expect many parents will continue to believe sugar causes
 bad behavior in children. They suggest that parents who are concerned about hyperactive children should not
 just blame sugar... but should take them to a doctor for an examination.

I am of the opinion that caffine affects different people differently. I have no scientific backing for this. I dated a guy who drank 4 or 5 cokes a day for years. After or while he drank them his personality changed completely from an cynical, quiet introvert to a chatty extrovert. When I brought this to his attention, he gave up the stuff. After giving up caffine he was the cynical, quiet introvert all of the time. rolls eyes He still drinks sugary pop. So I dont think the sugar played a part, unless caffine combined with sugar has some synergistic effect.

Me I drink a cup or two of coffee everyday. It just keeps me awake.

Apologies for not answering the OP directly, but it seems kind of relevant. For many years I was interested and concerned about the effects of various things, including caffeine. I was particularly annoyed at the vicious circle of tiredness: escape daytime dozyness via tea, coffee and cola; ensuing problems getting to sleep, or with poor quality sleep; wake up tired; repeat.

So I decided to cut them all out. No tea, no coffee, no Coke or other sodas.

I’m not someone renowned for willpower, but I found this surprisingly easy to do. I have nothing more scientific to offer than my own feelings, but it seemed to me to take about 3 days and nights before I got rid of the physical cravings\addiction i.e. felt fully de-caffeinated. And about 6-7 days before I got rid of the psychological addition i.e. was no longer thinking about these drinks.

Benefits? WONDERFUL quality of sleep: I drop off easily, it’s deep, relaxing stuff, and I need less of it. I wake up a-raring to go.

No tiredness during the day. Head feels very clear and okay.

And I’m happy to do without all those calories from things like the milk I used to put in the tea/coffee.

So, it can be done; it’s easier than you think, and there are some good benefits. Just my 0.02.

Well, FTR, if my kid eats a bizillion cookies, he doesn’t react like he does with Mountain Dew, so it prolly isn’t the sugar.

Also, FTR, I don’t drink caffeinated beverages much after 3 pm or so, and I never have trouble falling asleep, and I sleep very soundly – more soundly than my wife, who is 100% decaffienated.

My question was more along the lines of “why does caffiene (or other stimulants) affect certain people differently and/or more intensely?” Some of it, I’m sure, is acclimation to the stimulant, but even if I had too much caffeine, it would probably only make me irritable and maybe make it hard for me to get to sleep. It definitely wouldn’t make me a motor-mouth or incapable of sitting still.

How about trying these sites for hard info?

Caffeine 1

Caffeine: A Chemical Resource.

Caffeine Myths and Facts.

Caffeine Dependency Study.

These may help you out. :smiley:

Caffeine’s a drug, and as with other drugs, a certain level of tolerance is established after repeated ingestion. You mention that your wife and son kick into Speedy Gonzales mode after a little caffeine. Do they drink coffee or other caffeinated beverages as often as you do? If they don’t (and I get the impression that they don’t) then the caffeine will have a greater effect on them, simply because their bodies haven’t become tolerant of its effects as yours has.