Laterality of migraine and reported affect. The relevance of an hypothesis concerning the nature of migraine.
The few right-handed female subjects with exclusively left-sided classical migraine drawn from an epidemiological study have been found to be characterized by very low levels of anxiety and depression. This finding is examined in relation to the theory that migraine is a cerebral hemisphere response, ultimately vascular, to 'information overload' and that such specificity may be an indication of relatively high and selective hemisphere capacity and activity, left-sided in the above instance. There is also experimental evidence from elsewhere that unfettered or predominant left hemisphere activity is associated with reduction in depressive affect in normal subjects. This, then may be the basis of the present finding.