Episodic Migraine & Socioeconomic Status: Cause or Effect?
As a result of the large, groundbreaking American Migraine Prevalence and Prevention Study (AMPP) and other studies, we have known for some time there is a greater occurrence of Migraine among people with low socioeconomic status.
But this knowledge has always posed a "Which came first, the chicken or the egg?" quandary. In other words, do the situations associated with having low socioeconomic status make someone more likely to experience Migraine (social causation) or does living with Migraine cause the low socioeconomic status (social selection)? Using data from the AMPP study, researchers recently examined this important question with respect to episodic Migraine.
Researchers have believed both social causation and social selection are viable explanations. Since the onset of Migraine usually occurs in adolescence or young adulthood, we know this has a detrimental effect on the earning capability of Migraineurs (social selection). On the other hand, it is possible the stessors associated with low socioeconomic status make individuals prone to Migraine more likely to experience the condition (social causation).
The researchers assessed the AMPP data with the following ideas in mind:
- If social selection is the explanation, Migraine incidence and remission rates would not vary by income category.
- If social causation is the explanation, people in the lower income category would have higher incidence and lower remission rates when compared to higher income categories.
The research team believes its findings are consistent with the social causation theory of Migraine. Incidence and prevalence rates differed by income category. People in the bottom third of income were more likely to live with Migraine. In contrast, Migraine remission rates did not vary by income category.
Based on the results, the researchers believe:
- Migraine onset may be more likely to be associated with external factors.
- Migraine remission may be related to internal and/or genetic factors instead of external factors.
One major limitation of this study may lie in using income alone to determine the socioeconomic status of the research subjects. As discussed in an editorial accompanying this research study, it is more informative to use multiple factors to determine socioeconomic status to account for variability. For instance, people who despite having high levels of education have low incomes.
Further, chronic Migraine patients were excluded from this study. Thus, those whose income levels and socioeconomic status are most frequently and profoundly impacted by Migraine are not part of this study at all. However, the researchers chose not to include this group because of the small sample size of those with chronic Migraine in the original AMPP study.
While this study is certainly interesting and provides support for the idea that social causation plays an important role in Migraine, it does not settle the question of why people with low socioeconomic status are more likely than others to live with Migraine.
Can you tell when a migraine attack is coming?