Anxiety and depression are reported to be frequently associated with migraine but how they impact on migraine-related disability, migraine subjects' quality of life, and medical and therapeutic management of migraine attacks has not been investigated. FRAMIG 3 is a nation-wide population-based postal survey carried out in France according to the 2004 international classification of headache disorders. Subjects who had had migraine attacks during the last 3 months (subjects with 'active migraine', N = 1957) were analysed for migraine-related disability (MIDAS score), quality of life (SF-12 questionnaire), and anxiety and depression (Hospital Anxiety and Depression Scale [HADS]) in comparison with non-migraine subjects (N = 8287). Survey results indicate that 50.6% of subjects with active migraine were anxious and/or depressive (28.0% had anxiety alone, 3.5% depression alone, and 19.1% both anxiety and depression; P < or = 0.01 versus non-migraine subjects for anxiety alone and combined anxiety and depression, NS for depression alone). Although, migraine-associated anxiety and depression do not appear to influence the drugs taken by migraine subjects for the acute treatment of migraine attacks, perceived treatment efficacy and satisfaction with treatment are lower in subjects with anxiety alone or combined with depression than in subjects with neither anxiety nor depression. Anxiety and depression should be systemically looked for and cared for in subjects consulting for migraine.

Investigations of migraine comorbidity have confirmed its association with diverse psychiatric conditions. This association appears to be strongest for major depression and anxiety disorders (particularly panic and phobia), but increased comorbidity has also been reported with substance abuse and certain mood disorders. This literature also indicates that greater psychiatric comorbidity exists for migraine sufferers with aura than without. Some support is found for the notion that psychiatric comorbidity is higher in transformed migraine than in simple migraine (particularly in the case of chronic substance abuse). However, research into the possible mechanisms underlying these associations remains limited. Studies examining the order of onset and the cross-transmission of migraine and psychiatric disorders in families have been unable to distinguish fully between causal and common aetiological models of association. The conclusions are discussed in light of both methodological and conceptual issues relevant to understanding migraine comorbidity.

We set out to study the role of psychiatric comorbidity in the evolution of migraine to medication overuse headache (MOH) by a comparative study of 41 migraineurs (MIG) and 41 patients suffering from MOH deriving from migraine. There was an excess risk of suffering from mood disorders [odds ratio (OR) = 4.5, 95% confidence interval (CI) 1.5, 13.5], anxiety (OR = 5, 95% CI 1.2, 10.7) and disorders associated with the use of psychoactive substances other than analgesics (OR = 7.6, 95% CI 2.2, 26.0) in MOH compared with MIG. Retrospective study of the order of occurrence of disorders showed that in the MOH group, psychiatric disorders occurred significantly more often before the transformation from migraine into MOH than after. There was no crossed-family transmission between MOH and psychiatric disorders, except for substance-related disorders. MOH patients have a greater risk of suffering from anxiety and depression, and these disorders may be a risk factor for the evolution of migraine into MOH. Moreover, MOH patients have a greater risk of suffering from substance-related disorders than MIG sufferers. This could be due to the fact that MOH is part of the spectrum of addictive disorders.

In some cases, MOH thus appears to belong to the spectrum of addictive behaviors. In clinical practice, behavioral management of MOH should be undertaken besides pharmacological management.