title: Substance use disorders and psychotic disorders in epilepsy: a population-based registry study.
abstract: BACKGROUND
  Epilepsy affects around 70 million people worldwide. Psychiatric comorbidity may add to the burden of the disease. We studied substance use disorders and psychotic disorders among people with epilepsy from a population-based perspective.
  
  
  METHODS
  Norwegian specialist health services (hospitals and outpatient clinics) report diagnoses for individual patients to the Norwegian Patient Register. We used information on subjects born in 1930-1994 who were registered with a diagnosis of epilepsy at least once during the five-year period of 2008-2012. We compared the proportion of people with epilepsy registered with substance use disorders (alcohol use disorders or non-alcohol drug use disorders) and psychotic disorders (schizophrenia spectrum disorders or bipolar disorder) with similar figures in the population without epilepsy. We applied chi-square tests and log-binomial regression for analysis.
  
  
  RESULTS
  Overall, 0.90% of the Norwegian adult population was registered with epilepsy in somatic hospitals during 2008-2012. The total proportion registered with alcohol use disorder was 5.74% among people with epilepsy and 1.29% in the population without epilepsy (age- and sex-adjusted relative risk [RR]: 4.42, 95% confidence interval [CI]: 4.22-4.62). The corresponding figures were 4.32% and 1.22% (RR 3.86 [95% CI: 3.67-4.06] for drug use disorder, 1.72% and 0.60% (RR 2.94 [95% CI: 2.71-3.19]) for schizophrenia spectrum disorders, and 1.50% and 0.68% (RR 2.29 [95% CI: 2.10-2.49]) for bipolar disorder.
  
  
  CONCLUSIONS
  People with epilepsy were more often registered with substance use disorders and psychotic disorders than people without epilepsy. Psychiatric comorbidity requires particular attention in both diagnostic work-up and management of epilepsy, and creates complex medical challenges that require close cooperation between neurologists and psychiatrists. These findings may have implications for the organization and further development of comprehensive epilepsy care.
authors: Norwegian Institute of Public Health, Oslo, Norway. Electronic address: inger.johanne.bakken@fhi.no.
authors: Inger Johanne
authors: IJ
authors: Bakken
authors: Department of Neurology and Clinical Neurophysiology, St. Olav Hospital, Trondheim, Norway. Electronic address: eline.revdal2@stolav.no.
authors: Eline
authors: E
authors: Revdal
authors: Norwegian Institute of Public Health, Oslo, Norway. Electronic address: ragnar.nesvag@fhi.no.
authors: Ragnar
authors: R
authors: Nesvåg
authors: Department of Neurology and Clinical Neurophysiology, St. Olav Hospital, Trondheim, Norway; Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway. Electronic address: eiliv.brenner@ntnu.no.
authors: Eiliv
authors: E
authors: Brenner
authors: Norwegian Institute of Public Health, Oslo, Norway. Electronic address: gunpeggy.knudsen@fhi.no.
authors: Gun Peggy
authors: GP
authors: Knudsen
authors: Norwegian Institute of Public Health, Oslo, Norway. Electronic address: pal.suren@fhi.no.
authors: Pål
authors: P
authors: Surén
authors: Norwegian Institute of Public Health, Oslo, Norway. Electronic address: sara.ghaderi@fhi.no.
authors: Sara
authors: S
authors: Ghaderi
authors: Norwegian Institute of Public Health, Oslo, Norway. Electronic address: nina.gunnes@fhi.no.
authors: Nina
authors: N
authors: Gunnes
authors: Norwegian Institute of Public Health, Oslo, Norway. Electronic address: per.magnus@fhi.no.
authors: Per
authors: P
authors: Magnus
authors: Norwegian Institute of Public Health, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway. Electronic address: ted.reichborn-kjennerud@fhi.no.
authors: Ted
authors: T
authors: Reichborn-Kjennerud
authors: Norwegian Institute of Public Health, Oslo, Norway; Department of Global Public Health and Primary Care, University of Bergen, Norway. Electronic address: camilla.stoltenberg@fhi.no.
authors: Camilla Stoltenberg
authors: Norwegian Institute of Public Health, Oslo, Norway. Electronic address: lill.iren.trogstad@fhi.no.
authors: Lill Iren
authors: LI
authors: Trogstad
authors: Norwegian Institute of Public Health, Oslo, Norway. Electronic address: sirieldevik.haberg@fhi.no.
authors: Siri Eldevik
authors: SE
authors: Håberg
authors: Department of Neurology and Clinical Neurophysiology, St. Olav Hospital, Trondheim, Norway; Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway. Electronic address: eylert.brodtkorb@ntnu.no.
authors: Eylert
authors: E
authors: Brodtkorb
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004827:Epilepsy / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D011159:Population Surveillance / Q000379:methods; D011618:Psychotic Disorders / Q000175:diagnosis / Q000453:epidemiology*; D012042:Registries; D019966:Substance-Related Disorders / Q000175:diagnosis / Q000453:epidemiology*; D055815:Young Adult
keywords: Epidemiology; Epilepsy; Psychiatric comorbidity; Psychotic disorders; Substance use disorders