Introduction: Depression is a chronic and heterogeneous disorder manifesting itself by mood and sleep irregularities which ultimately can lead to suicide. Depressed individuals have a higher tendency to smoking compared to non-depressed people, and the interruption of this dependence produces even more depression. This situation may be reverted by the administration of anti-depressives and/or the use of nicotine replacement therapies. Taking into account these observations it will be explained how nicotine possibly acts in relation to two main neurotransmitters: serotonin and dopamine; and as a neuroprotective agent under a depressive condition. The effect of nicotine as a sleep regulator in depressed subjects will also be presented. AIM. To describe and discuss the evidences showing that nicotine has anti-depressive properties.
Development: In order of finding are presented in the following pages evidences showing that nicotine therapeutically can be used as an anti-depressive agent: general aspects of nicotine action (pharmacology, metabolism, nicotinic receptors), general features of depression, nicotine interactions in depressive disorders, and nicotine and the regulation of sleep.
Conclusions: Even though the basis of the relationship 'nicotine-depression' is not clear, the suggested anti-depressive role of nicotine involves a direct action over dopaminergic and serotoninergic activity or a possible indirect action as a neuroprotective agent, events which may have therapeutic effects on the quality of sleep and enhancement of depressive symptoms.