RESUMO
The placebo effect has been seldom studied in the history of medicine. However, during the last decades, the great impact of this phenomenon in clinical practice, ranging from surgical to psychiatric field, has been revealed. Research elucidated both the psychological mechanisms and genetic polymorphisms that affect the susceptibility of individuals to express this phenomenon. We herein review the psychological mechanisms, brain structures (anterior cingulate cortex, nucleus accumbens, dorsolateral prefrontal cortex, insular cortex, thalamus) and neurotransmission systems involved (opioid, dopaminergic, cannabinoid, serotoninergic, cholecystokinin). These are the clue to recognize the polymorphisms that have been identified so far. The biological basis of both the placebo effect and its alter ego, the nocebo effect, are well recognized, and related to corresponding psychological processes. Finally, the implications of the findings in clinical practice and medical training are discussed.
Assuntos
Efeito Placebo , Neurotransmissores/fisiologia , Dor/fisiopatologia , Dor/psicologia , Córtex Pré-Frontal/fisiologia , Neurotransmissores/genética , Efeito NoceboRESUMO
Recent advances in the study of alcoholism have thrown light on the involvement of various neurotransmitters in the phenomenon of alcohol addiction. Various neurotransmitters have been implicated in alcohol addiction due to their imbalance in the brain, which could be either due to their excess activity or inhibition. This review paper aims to consolidate and to summarize some of the recent papers which have been published in this regard. The review paper will give an overview of the neurobiology of alcohol addiction, followed by detailed reviews of some of the recent papers published in the context of the genetics of alcohol addiction. Furthermore, the author hopes that the present text will be found useful to novices and experts alike in the field of neurotransmitters in alcoholism.
Assuntos
Alcoolismo/genética , Dopamina , Glutamatos , Humanos , Neurobiologia/métodos , Neurotransmissores/genética , SerotoninaRESUMO
Obsessive-compulsive disorder (OCD) is characterized by recurrent and persistent thoughts (obsessions), and repetitive behaviors or mental acts (compulsions). In Korea, an epidemiological study reported that the lifetime prevalence of OCD in the population was greater than two percent. The exact cause of OCD is still unknown. Evidence from familial, twin and segregation studies supports the role of a genetic component in the etiology of OCD. In addition, there is growing evidence that OCD has a specific neurochemical and neuroanatomical basis. According to this evidence, researchers have selected various candidate genes which have been implicated in the neurophysiology of OCD, and differences of allelic variants in OCD patients and controls have been analyzed. In this review we will introduce the results of previous genetic studies of OCD which have been performed in other populations, including twin studies, family studies, segregation analyses, linkage analyses, and association studies. In addition to these studies, we will present the results of our genetic studies of OCD performed in Korea.