This study confirms prior reports of a strong association between migraine and sleep difficulties, with an approximately 3-fold increase in sleep problems among those with migraine. Not only did more people with migraine report specific sleep disturbances but they also had a greater number of sleep problems than their non-migraine counterparts. These findings contribute to current knowledge by demonstrating that the associations between migraine and sleep problems are not solely attributable to either current or lifetime comorbid anxiety and depression. The finding that relatives with migraine reported the same current sleep complaints as probands with migraine suggests that there may be a direct association between sleep disturbances and migraine.
Consistent with prior findings,8,9,11,12
probands with migraine reported that their sleep in general is inadequate, particularly with respect to difficulty falling asleep. In addition, the finding that those with migraine were characterized by multiple sleep problems suggests that migraine may be associated with poor sleep quality in general. Although anxiety and depression did not explain the sleep complaints of migraineurs, anxiety and depression were associated with difficulty falling asleep and inadequate sleep in the probands, and with difficulty falling asleep and staying asleep in the relatives. Persistent nightmares were not related to anxiety and/or depression in both the probands and relatives. This was not surprising as previous studies have reported little or no association between anxiety and nightmare frequency.37
Our finding that migraineurs reported more persistent nightmares has been recently reported in the child literature.38
Migraine attacks at night occur most frequently during late stages of sleep10,39
and transitions from rapid eye movement (REM) sleep periods,6
which may facilitate dream recall.40
In fact, one study found that dreams which culminate in migraine headaches were characterized by the presence of negative affect (ie, nightmares).41
Even in the absence of a nighttime headache attack, migraineurs may be more likely to remember their dreams since they are more likely to wake up during the night.11
Although the design and measures of the present study limit speculation on the possible explanations for the association between sleep problems and migraine, the 2 major classes of explanations for comorbidity are that one disorder is etiologically associated with the second or that the 2 conditions are manifestations of the common underlying pathways.42
In terms of causal mechanisms, migraine attacks that occur at night or during early morning hours could cause sleep problems, or conversely, a lack of sleep could provoke migraine attacks.43,44
Conversely, our finding of lifetime co-occurrence of migraine and childhood-onset nightmares and multiple sleep problems would be consistent with a common diathesis explanation. This mechanism would provide a compelling explanation in light of the persistent personality characteristics, autonomic lability,21
and hyperresponsiveness that tend to be stable characteristics of people with migraine.45
Irrespective of the explanations for the association between sleep problems and migraine, our findings have important clinical implications. First, the recognition and treatment of sleep problems in migraine patients may diminish the impact of migraine on daily functioning.46
Pharmacologic, relaxation, and cognitive behavioral treatments aimed to improve sleep as well as strategies to improve sleep hygiene may benefit migraine patients. Furthermore, if changes in sleep herald the onset of migraine, early intervention in this process could actually reduce the incidence of acute attacks of migraine.
The strengths of this study include: the recruitment of probands from both clinical and community settings, the systematic assessment of migraine, sleep problems and anxiety and mood disorders, and the inclusion of relatives, which constitutes a quasi epidemiologic sample. The original focus of this family study resulted in several limitations in the present analysis. Specifically, there was a lack of recruitment of migraine probands from clinical settings, a lack of information on migraine subtypes, severity and recency, and relatively small numbers. Furthermore, the cross-sectional design precluded evaluation of possible explanations for the order of onset of migraine, sleep problems, and anxiety and depression.
Nevertheless, these findings are intriguing and suggest that future studies should evaluate sleep problems in the context of both migraine and comorbid mood and anxiety disorders systematically. Prospective studies that seek to investigate the order of onset and persistence of these findings would provide insight into the possible explanations for these associations. For example, sleep problems were found to herald the onset of depression in a prospective study of a large population-based cohort by Dryman et al.47
Confirmation of these findings in other samples generated systematic intervention studies of sleep problems to reduce the incidence of episodes of major depression.48
However, no comparable studies of migraine and sleep problems have been conducted. Studies using tools such as actigraphy and daily headache diaries could provide insight into the associations found in this study.