title: Occurrence risk and structure of depression in Parkinson disease with and without dementia: results from the GEPAD Study.
abstract: BACKGROUND
  This study examined the age- and gender-specific risk of depression in demented and non-demented participants, its symptom structure, and associated clinical factors in a nationwide random sample of n = 1449 outpatients with Parkinson disease (PD).
  
  
  METHODS
  Depression ratings were based on a cross-sectional clinical assessment including the clinical Montgomery-Asberg Depression Rating Scale (MADRS > or = 14). Parkinson disease severity was rated according to Hoehn and Yahr (HY) and the Unified Parkinson's Disease Rating Scale. Diagnosis of dementia was based on Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition; DSM-IV) criteria.
  
  
  RESULTS
  25.2% (CI: 22.8-27.5) of all patients met study criteria for depression. Additionally, 8.4% of patients did not exceed the MADRS cut-off but were currently being treated with antidepressants, possibly suggesting a corrected (upper limit) total prevalence of 33.6%. Females were more likely depressive than males (29.3% vs 22.4%). In both genders, depression risk was elevated 2- to 4-fold depending on HY stage. Overall, highest rates in non-demented patients were found in females at stages IV to V (53.7%, CI: 37.7-69.6). Demented patients were more likely to meet depression criteria than non-demented (up to 76.2%, 95% CI: 60.5-87.9). Depression symptom profiles for demented PD patients (as compared to non-demented) revealed no structural differences but consistently higher symptom scores. Neither age at onset of PD nor duration of disease were significantly linked with depression.
  
  
  CONCLUSIONS
  Depression rates are already substantially elevated at early PD stages, emphasizing the need for a thorough examination of mood disorders in all patients with PD. Depression is associated with PD severity and dementia but not with age, age at onset of PD, or disease duration. The differential associations with dementia and the statistical independence of dementia and depression also suggest that depression could not be regarded as a mere demoralisation syndrome.
authors.affiliation: Technische Universitaet Dresden, Institute of Clinical Psychology and Psychotherapy, Dresden, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Riedel
authors.forename: Isabella
authors.initials: I
authors.lastname: Heuser
authors.forename: Jens
authors.initials: J
authors.lastname: Klotsche
authors.forename: Richard
authors.initials: R
authors.lastname: Dodel
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Wittchen
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003704:Dementia / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology / Q000523:psychology; D003863:Depression / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology* / Q000523:psychology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D005858:Germany; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D016017:Odds Ratio; D010300:Parkinson Disease / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology*; D015995:Prevalence; D011569:Psychiatric Status Rating Scales; D012307:Risk Factors; D012720:Severity of Illness Index; D012737:Sex Factors