Migraine and Depression Mix with Somatic Symptoms

TOLEDO, Ohio, Jan. 9 -- Migraine sufferers often have more than a headache, according to investigators here.

Women with chronic headaches are not only four times more likely to be depressed, they are also more likely to have other ills such as stomach or back pain, lack of energy, and trouble sleeping, found Gretchen E. Tietjen, M.D., of the University of Toledo, and colleagues, in a cross-sectional study.

These somatic symptoms remained significantly associated with chronic headache after adjusting for depression, suggesting that they are not a result of depression as some have thought, Dr. Tietjen and colleagues reported in the Jan. 9 issue of Neurology.

Many studies have reported a link between chronic headaches or migraines and depression, but few have examined how somatic symptoms fit into the mix, the researchers said.

The current study included 1,032 women seen at six different headache clinics during 2003 and 2004. The majority of these (90%) were diagnosed with migraines.

A total of 593 women suffered episodic headaches (less than 15 per month), and 439 had chronic headaches (15 or more per month). "Very severe" headaches were reported by 72% (n=742) of study participants.

Overall, 18% of study participants suffered from major depressive disorder. An additional 17% reported other depressive disorders. In chronic headache sufferers, the prevalence of major depressive disorder was 29%.

Compared with episodic headache sufferers, chronic headache suffers were significantly more likely to report symptoms of major depressive disorder (odds ratio=4.4; 95% confidence interval=2.9 to 6.5).

Chronic headache sufferers with the severest headache symptoms were six times more likely to report symptoms of major depressive disorder (OR=6.2; 95% CI=3.3 to 11.4).

Chronic headache sufferers were also more likely to experience somatic symptoms including stomach pain (OR=1.8; 95% CI=1.3 to 2.6), back pain (OR=1.7, 95% CI=1.2 to 2.3), pain or problems during intercourse (OR=1.8; 95% CI=1 to 3), feeling tired (OR=2.5; 95% CI=1.9 to 3.4), and trouble sleeping (OR=2.1; 95% CI=1.6 to 2.7).

The association between chronic headaches and overall somatic symptom severity remained significant after adjusting for depression (OR=1.7; 95% CI=1.2 to 2.4).

"Our finding that the association of somatic symptom severity with headache frequency, as well as with headache impact, remained significant after controlling for major depression suggests that somatic symptom severity and major depression are distinct variables," the authors said.

Analysis suggests a synergistic relationship of these variables," they continued. "We hypothesize that severe headache, severe somatic symptoms, and major depression may be linked through dysfunction of the serotonergic system, and studies are underway to test this theory."

However, the cross-sectional nature of the current study precludes establishing or considering a causal connection, they cautioned.

The study was limited by not including data on the exact frequency of headaches or use of any medications, such as antidepressants that might have, minimized the association between headache and depression.

They also pointed out that "since the instruments we used measured only current depression and somatic symptoms severity, our data do not allow us to establish a temporal sequence for onset headache and comorbid conditions."

Furthermore, "the inclusion of only female patients in this study limits the generalizability of the findings to other population," the authors said.