Smart Drinks are drinks made with nutrients that supply needed precursors and
cofactors that your body uses to manufacture neurotransmitters,the chemical
messengers that carry impulses in the brain.These neurotransmitters can 
frequently be depleted by heavy excercise,stress,stimulant drugs,or lack
of sleep, and many people report that amino acid/vitamin combo "smart drinks"
seem to help.
  An interesting sidenote to the smart drink story is that
a growing body of research seems to indicate that some of the nutrients
used in smart drinks may have value in helping people quit cocaine and
amphetamines.(Tennant 1985,Geis,Smith and Smith 1986,Hixson
1983,Dackis,Gold 1985,Wyatt,Karoum and Suddath 1988,Sved 1983)
This has sadly yet to be fully investigated.

Some nutrients used in "smart drinks" include:

L-Phenylalanine- An amino acid that is the precursor of tyrosine and hence
dopamine and norepinephrine, the main alerting neurotransmitters and those
most depleted by stress,stimulant drugs etc.
L-Phenylalanine is also the precursor of phenethylamine,a alerting amine
thought to modulate libido and agressive behavior.

L-Tyrosine-an amino acid and the most direct precursor of norepinephrine
and dopamine.This is the nutrient most used in recovery.

Choline(trimethylaminoethanol)- A B-complex vitamin that your body uses to
manufacture acetylcholine,
a neurotransmitter involved in the formation and recall of memories.

DMAE- (dimethylaminoethanol)- A B-complex nutrient that is used,like choline,
to manufacture acetylcholine in the body.DMAE is found in large quantities in
fish, and this is thought to be why people have always thought of fish as
"brain food".

In addition to fish,other natural foods that are high in "smart nutrients"
include soy products,almonds and other nuts,brewers yeast,some fruits,and

Two herbs that also have been associated with smart nutrition are
Ginko biloba and Siberian (eluthero) ginseng.