Saturday, September 1, 2012

Scientists find mania gene

In the past, psychological diseases were often regarded as something that cannot be explained on a biological level. Advances in our knowledge of the human body have made clear that this view is incorrect, as many disorders of a psychological nature have a biological background. Perhaps the most famous example is schizophrenia, of which a large portion can be explained by genetic effects. Now, scientists have uncovered the function of a gene that seems to be related to bipolar disorder, a disease characterized by heavy mood swings, varying from depression to mania. They showed that this particular gene is a causal factor for the manic episodes.

It was already known that a gene called NCAN plays a role in bipolar disorder, but its exact function has remained unknown so far. In order to uncover the characteristics of NCAN, the scientists looked both at patient data, as well as experimental animal models. That way it is possible to accurately predict the function of said gene. By correlating the human and mouse findings, the scientists hoped to create an accurate picture of NCAN's functions.

Statistical analysis showed that activity of the NCAN gene is negatively correlated with the manic symptoms in patients suffering from bipolar disorder. This means that a lower activity of the aforementioned gene is associated with increased mania. There was no statistical correlation with the symptoms of depression that patients with bipolar disorder suffer from. It seems that NCAN is therefore only responsible for the manic symptoms and only partly explains bipolar disorder.

In addition to the patient analysis, the researchers made an experimental mouse model: their animals had dysfunctional copies of the NCAN gene, which means it is possible to deduce its function by looking at what effect it has on the mice. The scientists noted that the so-called knockout mice had increased activity and risk-taking behaviour, which is fairly similar to the manic symptoms found in humans. Additionally, the knockout mice responded well to lithium treatment, which is frequently used to treat human patients as well. Because of the strong similarities with humans, the animal findings can be regarded as highly relevant.

Combining the patient and mouse data reveals that the NCAN gene is an important factor in order to explain bipolar disorder, although it only seemingly affects the manic episodes. Nevertheless, the scientists have shown a possible biological mechanism that underlies this peculiar mood-swing disorder. Because they also found a link with lithium, we may learn more about how this treatment works, as not all of its effects have been elucidated yet. All in all, the scientists think their study helps to find new targets for drugs to treat bipolar disorder.

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