Relatives of Epilepsy Patients Report Nearly Double Psychiatric Disease

Persons with epilepsy reported relatives with psychiatric diseases at nearly double the rate of matched population controls, with a relative risk of 1.98 (confidence interval 1.25–3.13). The finding comes from a questionnaire-based family history study published in Epilepsy & Behavior in December 2026, article 111267, by Johanna Annunen and colleagues at Oulu University Hospital and the University of Oulu, Finland.

The study drew on an all-cause epilepsy cohort of 508 persons with epilepsy (PWEs), previously identified among participants in earlier epilepsy studies at Oulu University Hospital. Each cohort member received a structured questionnaire covering neurologic and psychiatric symptoms and diseases in their family. Of the 508, 172 agreed to participate.

Researchers then identified five peers per patient, matched on age, sex and home municipality, from the Finnish Population Register Centre. Those 884 control individuals received similar written questionnaires, and 168 participated. The design therefore compares 172 patients against 168 matched controls drawn from the same population base.

What did the questionnaire find?

Patients with epilepsy were more likely than controls to report a relative with migraine (relative risk 1.32, CI 1.07–1.63) or with psychiatric diseases (RR 1.98, CI 1.25–3.13). Relative risk expresses how much more frequently a condition appears in one group compared with another.

The differences extended further among women. Women with epilepsy were more likely than controls to report relatives with epilepsy or with symptoms referring to epilepsy (RR 1.66, CI 1.14–2.42), and relatives with movement disorder symptoms (RR 2.30, CI 1.35–3.91).

The authors summarize the direction of the results plainly: patient-reported rates of neurologic and psychiatric symptoms and diseases were higher in families of persons with epilepsy than in families of population-based matched control subjects.

What does this change for clinical practice?

The study relied on self-reported family history rather than verified registry diagnoses or EEG-confirmed classifications, so the figures reflect patient recall, not clinically validated diagnoses. That limitation matters when interpreting the size of the associations.

Even so, the authors argue the findings carry a practical message for everyday clinical work: knowledge of the possibly increased disease burden in families of persons with epilepsy promotes recognition of these conditions in clinical settings. For neurologists and clinical neurophysiology staff taking histories in the epilepsy monitoring unit or outpatient clinic, a structured family history covering migraine, psychiatric disease, movement disorder symptoms and epilepsy in relatives may surface comorbidities that shape management.

The article, published open access under a Creative Commons license, is part of Volume 185 of Epilepsy & Behavior. Future work using national register linkages rather than patient recall could establish whether the reported family aggregation holds against verified diagnostic data.