Many scientists believe that both disorders share some of the same biological factors. Past research has hinted at a two-way relationship between migraines and depression, and the latest study adds evidence to this idea.
The study was headed up by Dr Naomi Breslau, of the Henry Ford Health System in Detroit. The results were published in the journal Neurology.
Establishing the major depression-migraine link
Breslau believes that understanding the association between major depression and migraines might have important clinical implications, providing clues as to ways to ease both disorders.
The study found that, over a period of two years, migraine sufferers were five times more likely than normal people to develop major depression. And visa versa – participants suffering from depression at the start of the study had over a three-fold higher chance of developing migraines.
Breslau's team interviewed 496 adult migraine sufferers, 151 people that suffered from severe headaches but not migraines, and 539 people who didn't have a history of headaches or migraines. All 1186 people were followed for two years.
Before the study began, 42% of the participants in the migraine group had experienced major depression at some point in their lives, as did 36% of the people in the severe-headache group. Only 16% of the group that didn't have a history of headaches had suffered from major depression.
What is major depression?
Cape Town psychologist Ilse Pauw, defines major depression as a combination of most or all of the following symptoms: depressed mood, A lack of interest or pleasure in activities that one used to find enjoyable, low self esteem, insomnia or hypersomnia, a marked increase or decrease in appetite, difficulty in concentrating or decision-making, constant negative or suicidal thoughts, lack of energy, feelings of worthlessness or inappropriate guilt and/or psychomotor agitation or retardation (that is being either too jittery or too listless).
Breslau's team discovered that major depression also seemed to increase the risk of one's first migraine and that migraine history had the same effect on the risk of an initial bout of depression.
Other interesting findings
In Neurology, the researchers conclude that their findings "indicate that the relationship between migraine and major depression is bi-directional, with each disorder increasing the risk for the subsequent first onset of the other".
They also say that their study does not support the theory that major depression is a psychological response to chronic headaches. "If major depression in persons with migraine were caused by the pessimism and distress associated with recurrent severe headaches, we should have observed the same increased risk also in persons with other headaches of similar severity," the study authors write.
Same biological foundations
The authors also point out that if migraines were merely a physiological symptom of major depression, then they would also have observed a higher risk of other kinds of headaches in people with a history of depression.
But in actual fact, the researchers' findings support the concept that the two disorders share the same biological foundations, perhaps related to brain chemicals or hormones that transmit nerve signals.
If you have one, you might have the other
Breslau and her colleagues recommend that if you suffer from either disorder, you should be evaluated to see whether you have the other one.
The good news is that "treatments that might improve both migraine and major depression may benefit patients with both disorders". (Health24)