title: Validity of the PHQ-2 for the screening of major depression in Parkinson's disease: two questions and one important answer.
abstract: BACKGROUND
  Depression is the most common psychiatric comorbidity in Parkinson's disease (PD), but is often under-diagnosed and under-recognized.
  
  
  OBJECTIVE
  To evaluate and compare the psychometric qualities of the Patient Health Questionnaire (PHQ-2) and the depression item of the Unified Parkinson's Disease Rating Scale (UPDRS).
  
  
  METHODS
  Cross-sectional study conducted at a movement disorders outpatient clinic. One hundred ten patients with a diagnosis of PD without dementia were evaluated. A neurologist administered the PHQ-2 and the UPDRS, and the diagnosis of major depression was performed using the structured clinical interview for DSM disorders - clinical version. Two self-rating scales (Zung Self-rating Depression Scale and 15-item Geriatric Depression Scale) were also used.
  
  
  RESULTS
  The prevalence of current depression in the sample was 25.5% (n = 28). The scores of the PHQ-2 discriminated between subjects with and without depression, with an area under the receiver operating characteristic curve of 0.90. The sensitivity and specificity for a cut-off score of three were 75% and 89%, respectively. The values for the depression item of the UPDRS were slightly lower.
  
  
  CONCLUSIONS
  The PHQ-2 is a valid tool for screening depression in PD.
authors.affiliation: Department of Neuroscience and Behavior of the Ribeirão Preto Medical School, University of São Paulo, INCT Translational Medicine, Brazil. setroh@hotmail.com
authors.forename: Marcos H N
authors.initials: MH
authors.lastname: Chagas
authors.forename: José A S
authors.initials: JA
authors.lastname: Crippa
authors.forename: Sonia R
authors.initials: SR
authors.lastname: Loureiro
authors.forename: Jaime E C
authors.initials: JE
authors.lastname: Hallak
authors.forename: Carolina de
authors.initials: Cd
authors.lastname: Meneses-Gaya
authors.forename: João P
authors.initials: JP
authors.lastname: Machado-de-Sousa
authors.forename: Guilherme R
authors.initials: GR
authors.lastname: Rodrigues
authors.forename: Alaor S
authors.initials: AS
authors.lastname: Filho
authors.forename: Rafael F
authors.initials: RF
authors.lastname: Sanches
authors.forename: Vitor
authors.initials: V
authors.lastname: Tumas
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D003865:Major Depressive Disorder / Q000150:complications / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000523:psychology*; D011594:Psychometrics / Q000295:instrumentation; D012680:Sensitivity and Specificity