Acute nicotine administration and acute nicotine withdrawal have been shown
to have effects on mood, arousal, and cognition in humans. However, given
what is known about the interrelationships between mood, arousal, and cogni
tion in the psychology literature, it is unclear to what extent these effec
ts on a given response are direct. or mediated through other responses (ind
irect). This article discusses this issue with particular emphasis on the q
uestion of whether nicotine has direct effects on cognition. Five ways are
suggested as to how this question can be resolved, the relevant literature
is reviewed, and some research ideas are proposed. (C) 2000 Elsevier Scienc
e Ltd.