[Nicotine as an antidepressant and regulator of sleep in subjects with depression]. / Acción de la nicotina como antidepresivo y regulador del sueño en sujetos deprimidos.

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.

Acción de la nicotina como antidepresivo y regulador del sueño en sujetos deprimidos / Nicotine as an antidepressant and regulator of sleep in subjects with depression

Resumen. Introducción. La depresión es un trastorno heterogéneo crónico que se manifiesta por irregularidades en el humor y sueño que pueden llevar al suicidio. Individuos deprimidos tienden a fumar más que los no deprimidos y la interrupción de este hábito produce una depresión mayor que se revierte con el uso de antidepresivos o terapias de reemplazo de nicotina. Basándonos en estos hallazgos, explicaremos cómo actúa posiblemente la nicotina sobre dos neurotransmisores principales (serotonina y dopamina), y como neuroprotector en procesos depresivos, además de exponer el efecto de la nicotina como regulador de sueño en sujetos deprimidos. Objetivo. Describir y discutir las evidencias que han demostrado que la nicotina tiene propiedades antidepresivas. Desarrollo. Se presenta el orden de los hallazgos que demuestran que la nicotina puede utilizarse como antidepresivo: aspectos generales de la nicotina (farmacología, metabolismo y receptores nicotínicos), características generales de la depresión, mecanismo de interacción de la nicotina en los trastornos depresivos, y nicotina y regulación del sueño. Conclusiones. A pesar de que la base neurobiológica de esta asociación ‘nicotina-depresión’ no es clara, el mecanismo antidepresivo sugerido para la nicotina involucra su acción directa sobre la actividad dopaminérgica y serotoninérgica o su posible acción indirecta como neuroprotector, lo que origina efectos terapéuticos sobre la calidad de sueño y mejora de los síntomas depresivos (AU)

Summary. 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 antidepressive 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 (AU)