09/11/2012 10:25 am ET

NCAN: Scientists Identify Gene Linked With Mania In Bipolar Disorder

Scientists have identified a gene that seems to play a role in the manic episodes experienced during bipolar disorder, according to a new study.

The finding, published in the American Journal of Psychiatry, shows that the NCAN gene seems to be linked with mania. Bipolar disorder is characterized by mood swings, where a person may have feelings of extreme highs -- mania -- followed by feelings of extreme depression, according to the Mayo Clinic.

The new study is based on 1,218 people with bipolar disorder; though some had more manic components of the disorder, while some had more depressive components of the disorder. The researchers from University of Bonn and the Central Institute of Mental Health in Mannheim found that the manic symptoms from bipolar disorder were linked with the NCAN gene, but the depressive symptoms were not.

The researchers also conducted experiments in mice to find the association between NCAN and mania. They experimented with mice whose NCAN gene was "knocked out" -- meaning the gene is no longer functioning -- and found that they were more hyperactive than regular mice, nor did they exhibit any signs of depression.

And when the researchers fed these engineered mice lithium -- which is what is used to treat humans with bipolar disorder -- the mice stopped their manic behavior.

"We were quite surprised to see how closely the findings for mice and the patients correlated," study researcher Dr. Markus M. Nöthen, director of the Institute of Human Genetics, said in a statement.