Lead. People who overuse headache painkillers are significantly more likely to suffer from chronic insomnia and restless legs syndrome, a new prospective case-control study finds. And the good news: when the underlying headache problem is treated, those sleep disorders largely resolve on their own.
The study, published in the European Journal of Neurology, is the first to systematically measure the prevalence of sleep disorders in medication-overuse headache (MOH) and to track what happens to those sleep problems after patients receive appropriate headache treatment. The findings suggest that for millions of people trapped in a cycle of daily or near-daily headaches and frequent analgesic use, fixing the headache may be the key to fixing the sleep.
What they found. Researchers at a specialized headache center in Russia enrolled 171 patients with medication-overuse headache and 173 control patients who had headache disorders of similar type and severity but did not overuse acute medication. The groups were closely matched for age (mean 43.3 years) and sex (about 82% female). Migraine was the most common underlying headache disorder, affecting roughly two-thirds of both groups.
The results were striking. Chronic insomnia was present in 60.2% of MOH patients versus 47.4% of controls, yielding an odds ratio of 1.7 (95% CI 1.1-2.6, p=0.03). Restless legs syndrome was even more disproportionately common: 37.4% of the MOH group met diagnostic criteria, compared with 22.0% of controls (OR 2.1, 95% CI 1.3-3.4, p=0.003). Both differences were statistically significant, meaning they are unlikely to be due to chance.
The researchers also identified factors within the MOH group that were independently associated with chronic insomnia. After multivariate adjustment, four variables remained significant: nocturnal headache (OR 2.0), nighttime analgesic use (OR 2.5), overweight or obesity (OR 2.7), and arterial hypertension (OR 2.6). Notably, the strongest predictors were modifiable: body weight and the behavior of taking painkillers at night.
Perhaps the most compelling finding came from follow-up data. Of the original 171 MOH patients, 87 completed a structured withdrawal and preventive treatment program and were reassessed after a mean of 24.2 months. The improvements were dramatic. Chronic insomnia prevalence dropped from 60.2% to 33.3% (p<0.001). Restless legs syndrome fell from 37.4% to 14.9% (p<0.001). These reductions closely paralleled improvements in headache frequency and the sharp decline in monthly analgesic intake, suggesting a direct link between breaking the medication-overuse cycle and sleep recovery.
Why it matters. Medication-overuse headache is one of the most common and disabling headache disorders worldwide, affecting an estimated 1-2% of the general population. It arises when people with primary headache disorders (most often migraine or tension-type headache) take acute pain medication too frequently, typically 10-15 or more days per month, depending on the drug class. The medications stop working as well, the headaches become more frequent, and the patient takes more medication, creating a self-perpetuating loop.
Sleep disruption has long been recognized as both a trigger and a consequence of headache, but the scale and specificity of the problem in MOH patients had not been well characterized. This study provides some of the strongest evidence yet that sleep disorders are not merely comorbid but are in fact dynamically linked to MOH itself. The fact that chronic insomnia and RLS both improved substantially after MOH treatment, without any sleep-specific intervention, strongly suggests that the medication-overuse behavior and the headache burden are driving the sleep problems, not the other way around.
For clinicians, the message is clear. When a patient presents with chronic daily headache and heavy analgesic use, screening for insomnia and restless legs syndrome should be part of the workup. More importantly, both patient and doctor can be reassured that these sleep disturbances are reversible. Treating the MOH by withdrawing the overused medication and starting appropriate preventive therapy may be sufficient to normalize sleep in a majority of patients, avoiding the need for separate sleep interventions.
There is a practical implication as well. Nighttime analgesic use was one of the strongest independent predictors of chronic insomnia in the MOH group, carrying an odds ratio of 2.5. This suggests that the common practice of taking painkillers at bedtime to prevent nocturnal headache or to treat pain that wakes the patient may actually be counterproductive, potentially disrupting sleep architecture and perpetuating the cycle. Clinicians should counsel patients to avoid this habit and should explore alternative strategies for nocturnal headache management.
Limits. The study has several limitations worth noting. First, all participants were recruited from a single specialized headache center in Russia, which may limit generalizability to other populations and healthcare settings. Second, the sample was predominantly female and middle-aged, reflecting the typical demographic of MOH patients but making it difficult to draw conclusions about men or younger or older age groups. Third, sleep disorders were assessed using validated questionnaire-based diagnostic criteria rather than objective measures such as polysomnography or actigraphy, raising the possibility of recall bias or misclassification. Fourth, the follow-up cohort of 87 patients represents just over half of the original MOH group, and those lost to follow-up may have differed in important ways from those who completed the program, potentially introducing attrition bias. Finally, the observational design means that while the temporal relationship is suggestive, causality cannot be definitively established.
Bottom line. Chronic insomnia and restless legs syndrome are highly prevalent in medication-overuse headache and are significantly more common than in headache patients who do not overuse acute medication. Both conditions improve substantially after standard MOH treatment (withdrawal of overused medication combined with preventive therapy), without requiring any targeted sleep intervention. The findings add weight to the argument that medication-overuse headache is a systemic disorder with consequences that extend well beyond the head, and they offer real hope to patients caught in the MOH cycle: treat the headache, and the sleep may fix itself.
Source. Lebedeva ER, Kniazeva IA, Gilev DV, Olesen J. Sleep disorders in medication-overuse headache: a prospective case-control study. European Journal of Neurology. 2026;33(7):e70685. doi:10.1111/ene.70685. PMID: 42460796.