A new study from the Journal of Molecular Psychiatry has found evidence of significantly different gene expressions in the striatum brain structure for those with bipolar disorder.
Genes of bipolar participants in the study were expressed differently for this brain region than the genes of participants without a history of bipolar symptoms. Because this was the first study to measure and find such differences, not much is known about the specific differences in gene expression and what they each could mean. The findings will also need to be validated by future studies to become generally accepted knowledge. However, the striatum as a whole is known to play a role in motivation arising from perceived rewards and risks. As the study's authors highlight, over-valuing rewards and de-emphasizing risks may be part of what causes impulsive behaviors during periods of mania.
This was also the first study to find differences in a sub-cortical brain structure, or one tied more to emotions and motivations than to abstract thought, for those who have been diagnosed with bipolar disorder. Further differences appeared for genes linked to cellular energy and the body's immune system and inflammation responses.
Ron Davis, the director of the study, reminds us that "We don't know if these changes are a cause of the disease or the result of it. But they provide additional gene markers in bipolar disorder that could potentially lead to the future development of diagnostics or treatments."