title: Comorbidity was associated with neurologic and psychiatric diseases: a general practice-based controlled study.
abstract: OBJECTIVE
  To comprehensively examine comorbidity in unselected cohorts of patients with depression, stroke, multiple sclerosis (MS), Parkinson's disease/parkinsonism (PD/PKM), dementia, migraine, and epilepsy.
  
  
  METHODS
  This cross-sectional study used morbidity data recorded by Dutch general practitioners. Index disease cohort sizes ranged from 241 patients with MS to 6,641 patients with lifetime depression. Thirty somatic and seven psychiatric disease categories were examined to determine whether they were comorbid with the index diseases by performing comparisons with age- and gender-matched control cohorts. Identified comorbidities were classified as either "possible" or "highly probable" comorbidity.
  
  
  RESULTS
  An extensive range of 26 disease categories was found to be comorbid with lifetime depression. The comorbidity profile of stroke was also wide, including 21 disease categories. The comorbidity patterns of migraine and epilepsy comprised each 11 disease categories. Those concerning MS, PD/PKM, and dementia included a small number of disease categories.
  
  
  CONCLUSIONS
  This study provides comprehensive knowledge of the occurrence of somatic and psychiatric comorbidity in general populations of patients with depression, stroke, MS, PD/PKM, dementia, migraine, and epilepsy. The implications of the findings for clinical practice and research are discussed.
authors.affiliation: NIVEL (Netherlands Institute for Health Services Research), Otterstraat 118124, P.O. Box 1568, 3500 BN, Utrecht, The Netherlands. j.nuijen@nivel.nl
authors.forename: Jasper
authors.initials: J
authors.lastname: Nuyen
authors.forename: François G
authors.initials: FG
authors.lastname: Schellevis
authors.forename: William A
authors.initials: WA
authors.lastname: Satariano
authors.forename: Peter M
authors.initials: PM
authors.lastname: Spreeuwenberg
authors.forename: Merrill D
authors.initials: MD
authors.lastname: Birkner
authors.forename: Geertrudis A M
authors.initials: GA
authors.lastname: van den Bos
authors.forename: Peter P
authors.initials: PP
authors.lastname: Groenewegen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D015331:Cohort Studies; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003704:Dementia / Q000453:epidemiology; D003863:Depression / Q000453:epidemiology; D004827:Epilepsy / Q000453:epidemiology; D005194:Family Practice; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000453:epidemiology*; D008875:Middle Aged; D008881:Migraine Disorders / Q000453:epidemiology; D009103:Multiple Sclerosis / Q000453:epidemiology; D009422:Nervous System Diseases / Q000453:epidemiology*; D009426:Netherlands / Q000453:epidemiology; D010300:Parkinson Disease / Q000453:epidemiology; D012189:Retrospective Studies; D020521:Stroke / Q000453:epidemiology