Conventional wisdom holds that bad headaches lead to bad moods, but a new study points to a genetic link between the two. "Most people think that migraine patients are depressed because they have headaches," one researcher tells Time. "We found that there is a genetic predisposition by people with migraines to be depressed."
The researchers focused on a group of people descended from 22 related couples in the Netherlands: About 25% of family members with migraines were depressed, versus just 12% of relatives without migraines. Overall, those with migraines were 1.4 times as likely to suffer from migraines and depression together rather than migraines alone. The team is now looking for the specific genes at play, which could help treat both conditions.
(Read more migraines stories.)