Glass Half-Full, or Half-Empty? Ask Your Genes

Bad—or, potentially, good—news for pessimists: Some people's negative outlook on life appears to be caused by a genetic condition, according to a new study. Researchers found that people with low levels of the brain chemical NPY are likelier to be pessimistic, to deal poorly with stress, and to suffer from major depression, the Telegraph reports.

People with low levels of NPY were found to have a stronger emotional response to negative stimuli, WebMD reports. The mechanism appears to be independent of other biological causes of depression, say researchers, who hope their findings will help produce more effective therapies. "These are genetic features that can be measured in any person. We hope they can guide us toward assessing an individual's risk for developing depression," the lead researcher says. (More depression stories.)