MIGRAINE AND DEPRESSION - BIOLOGICAL ASPECTS

There is a considerable overlap in migraine and depression incidence, and both conditions may be associated with low levels of 5-hydroxytryp tamine (5-HT). During a migraine attack there is evidence for low leve ls of platelet 5-HT and possibly also low Vmax for 5-1 IT uptake; both these findings are also associated with the depressed state. Both con ditions can be treated by tricyclic and monoamine oxidase inhibiting a ntidepressants. However, there are also clear differences: migraine at tacks are brief and self limiting. Part of the migraine cascade occurs outside the blood brain barrier, presumably involving blood vessels a nd, unlike depression, migraine attacks can be ameliorated by drugs wh ich only act peripherally. In addition, migraine patients, especially males, often have permanently low levels of platelet monoamine oxidase activity, whereas patients with unipolar depression tend to have rais ed levels of this marker. This low enzyme activity may reflect part of the vulnerability to migraine, often associated in the prodromal phas e with agitation or hyperactivity. Migraine may form part of a family of brief recurrent self-limiting disorders, which involve disturbances of both mood and monoamines; during the headache phase of the attack, the links with depression are most apparent.