An experiment has found differences between the brains of progressives and conservatives.

Head scans of students at University College London, conducted by neuroscientist Geraint Rees, showed a “strong correlation” between thickness in two regions, the amygdala and the anterior cingulate, and political viewpoint.

MIT neuroscientists have shown they can influence people’s moral judgments by disrupting a specific brain region – a finding that helps reveal how the brain constructs morality.

“You think of morality as being a really high-level behavior,” she says. “To be able to apply (a magnetic field) to a specific brain region and change people’s moral judgments is really astonishing.”

Use of antidepressant drugs in the United States doubled between 1996 and 2005, probably because of a mix of factors, researchers reported on Monday.

About 6 percent of people were prescribed an antidepressant in 1996 – 13 million people. This rose to more than 10 percent or 27 million people by 2005, the researchers found.

“Significant increases in antidepressant use were evident across all sociodemographic groups examined, except African Americans,” Dr. Mark Olfson of Columbia University in New York and Steven Marcus of the University of Pennsylvania in Philadelphia wrote in the Archives of General Psychiatry.

“Not only are more U.S. residents being treated with antidepressants, but also those who are being treated are receiving more antidepressant prescriptions,” they added.

More than 164 million prescriptions were written in 2008 for antidepressants, totaling $9.6 billion in U.S. sales, according to IMS Health.

Antidepressant medications appear to help only very severely depressed people and work no better than placebos in many patients, British researchers said.

The researchers found that compared with placebo, these new-generation antidepressant medications did not yield clinically significant improvements in depression in patients who initially had moderate or even very severe depression. The study found that significant benefits occurred only in the most severely depressed patients.