Women with migraines are more likely to be depressed, according to a study of headache clinic patients.

Migraines are severe throbbing headaches that can cause vomiting, nausea and a sensitivity to light, sound and smells. No one knows what causes migraines.

Women with chronic headaches were four times more likely than episodic headache sufferers — those experiencing fewer than 15 headaches per month —  to report symptoms of major depression.

"Painful physical symptoms may provoke or be a manifestation of major depression in women with chronic headache, and depression may heighten pain perception," said study author Dr. Gretchen Tietjen of the University of Toledo-Health Science Campus.

"This relation between migraine and major depression suggests a common neurobiology."

A total of 1,032 women with headaches completed the survey, 593 with episodic (96 per cent with migraine) and 439 with chronic headache (87 per cent with migraine).

Chronic headache sufferers were also three times more likely to report headache-related symptoms such as:

• Low energy.
• Trouble sleeping.
• Nausea.
• Dizziness.
• Pain or problems during intercourse.
• Pain in the stomach, back, arms, legs and joints.

The likelihood of major depression jumped 32-fold among patients diagnosed with severely disabling migraines who reported other severe symptoms.

Other studies are underway to test whether serontonin dysfunctions in the central nervous system are common to severe headaches, other physical symptoms and major depression.

About 3.5 million Canadians are believed to suffer from migraines.