Risk for schizophrenia and schizophrenia-like psychosis among patients with epilepsy: population based cohort study -- Qin et al. 331 (7507): 23 -- BMJ

Risk for schizophrenia and schizophrenia-like psychosis among patients with epilepsy: population based cohort study -- Qin et al. 331 (7507): 23 -- BMJ: "Risk for schizophrenia and schizophrenia-like psychosis among patients with epilepsy: population based cohort study
Ping Qin"
The association between epilepsy and psychosis has been researched since the nineteenth century. Several studies1-4 but not all5 6 have found a higher prevalence of schizophrenia-like psychosis in patients with epilepsy compared with the general population. Yet many questions remain unanswered and large scale studies using empirical data are scant.7 The causal mechanism underlying the association is unclear. Seizures may damage the brain, which may in turn increase the risk of schizophrenia-like psychosis, or the two conditions may share common aetiological factors. These hypotheses may be disentangled by evaluating the risk of schizophrenia-like psychosis in people with a family history of epilepsy.8 Genetic vulnerability to psychosis may facilitate the development of psychosis in the patients with epilepsy.9 10 However, there have been no published family history studies with appropriate methods.8 In addition, differences in risk of developing psychosis—for example, by type of epilepsy, age at onset, and number of admission to hospital—remain poorly understood.

In this population based cohort study we examined the risk of schizophrenia or schizophrenia-like psychosis associated with a history of epilepsy using data from Danish longitudinal registers. We also investigated how and to what extent this risk is influenced by family histories of psychosis and of epilepsy.