Researchers have discovered how genes trigger manic symptoms of bipolar disorder.
People suffering from bipolar disorder alternate between two extreme states, depressive phase which includes depression, diminished drive and suicidal thoughts and manic phase, marked by restlessness, euphoria, and delusions of grandeur.
Researchers from the University of Bonn and the Central Institute of Mental Health, Mannheim Germany, have now discovered, based on patient data and animal models, how the NCAN gene triggers manic symptoms of bipolar disorder.
The genesis of this disease probably has both hereditary components as well as psychosocial environmental factors.
"It has been known that the NCAN gene plays an essential part in bipolar disorder," Markus M. Nothen, professor of human genetics at the University of Bonn, was quoted as saying in The American Journal of Psychiatry.
"But until now, the functional connection has not been clear."
In a large-scale study, researchers led by Bonn and the Central Institute have now shown how the NCAN gene contributes to the genesis of mania, according to a Bonn statement.
They based their findings on an analysis and evaluation of the genetic data and the related descriptions of symptoms from 1,218 patients with differing ratios between the manic and depressive components of bipolar disorder.
A team working with Andreas Zimmer, professor at the Institute of Molecular Psychiatry, University of Bonn, examined the molecular causes effected by the NCAN gene. They studied mice in which the gene had been "knocked out."
"It was shown that these animals had no depressive component in their behaviours, only manic ones," said Zimmer.
These knockout mice were considerably more active than the control group (with the NCAN gene) and showed a higher level of risk-taking behaviour.
Finally, researchers gave the manic knockout mice lithium - a standard therapy for humans.
"The lithium dosage completely stopped the animals' hyperactive behaviour," reported Zimmer.
The results also matched for lithium; the responses of humans and mice regarding the NCAN gene were practically identical.