Tobacco smoking is an extremely addictive and harmful form of nicotine (NIC) consumption,
but unfortunately also the most prevalent. Although disproportionately high frequencies
of smoking and its health consequences among psychiatric patients are widely known,
the neurobiological background of this epidemiological association is still obscure.
The diverse neuroactive effects of NIC and some other major tobacco smoke constituents
in the central nervous system may underlie this association. This present paper summarizes
the pharmacology of NIC and its receptors (nAChR) based on a systematic review of
the literature. The role of the brain's reward system(s) in NIC addiction and the
results of functional and structural neuroimaging studies on smoking-related states
and behaviors (i.e. dependence, craving, withdrawal) are also discussed. In addition,
the epidemiological, neurobiological, and genetic aspects of smoking in several specific
neuropsychiatric disorders are reviewed and the clinical relevance of smoking in these
disease states addressed.