%0 Journal Article
%T Genomic studies of mood disorders - the brain as a muscle?
%A Alexander B Niculescu
%J Genome Biology
%D 2005
%I BioMed Central
%R 10.1186/gb-2005-6-4-215
%X Mood - the way one feels inside emotionally - is likely to have evolved, broadly speaking, as a sensor and integrator of the environmental availability, or lack of availability, of resources that an organism needs to live, to develop and to propagate its genes. A non-nurturing, hostile environment engenders low mood and depression. This is useful in making the organism conserve existing resources, keep still and stay out of harm's way [1,2]. Conversely, a nurturing, favorable environment engenders high mood and euphoria, making the organism more likely to take advantage of opportunities, to expand and to propagate its genes. The switch from low to high mood becomes loose in bipolar (manic-depressive) illness, and overreacts to minor stimuli in an excessive and persistent fashion that often obscures any correlation with external events that trigger the switch. The incongruence between mood and environment is a hallmark of severe clinical depression or mania. In severe clinical depression (also called major depressive disorder), mood is low even in favorable conditions, whereas in mania, mood is high even in unfavorable conditions. Extremes of mood are often associated with cognitive distortions (psychotic symptoms).Mood disorders have been studied primarily in humans, although aspects of them can be found in other animals and can be studied in rodent models, for example [3]. They are the result of a complex interaction between genes and the environment, and some people are more susceptible than others, whether for genetic or other reasons (such as developmental insults or stressors). Little is currently known about the genes involved in susceptibility to mood disorders [4]. Brain-imaging studies have shown that the regions of the brain that are important in mood regulation include the prefrontal cortex and the hippocampus, and depression has been linked with a decrease in volume of these parts of the brain. Depression can be treated with a range of antidepressant dru
%U http://genomebiology.com/2005/6/4/215