title: Comparing depression diagnostic symptoms across younger and older adults.
abstract: OBJECTIVE
  Depression in later life has potential grave implications and contributes to heavy emotional, medical, and economic burdens. Therefore, it is not surprising that identifying depression and its symptoms in later life has remained a sustained concern for professionals who treat older patients. Despite this concern, the current diagnostic gold standard may not identify depression symptoms equally well in older and younger adults. The objective of this analysis is to determine whether older and younger adults with equivalent levels of latent depression are equally likely to endorse particular DSM diagnostic symptoms.
  
  
  METHODS
  We analyzed DSM depression data using Item Response Theory (IRT)-based differential item functioning analyses. The data came from 1808 older adults (age 65-98 years) and 3734 younger adults (age 18-34 years) who participated in the National Epidemiological Survey on Alcoholism and Related Conditions.
  
  
  RESULTS
  The analyses confirmed our hypothesis. The DSM items identify depression differently in younger and older adults. Specifically, results showed that older adults were more likely to endorse somatic items and less likely to endorse cognitive and suicide items than their younger counterparts with equivalent levels of depression.
  
  
  CONCLUSIONS
  These findings provide evidence that the DSM depression items work differently across age groups when controlling for latent depression. It is important to consider, however, that these findings are limited by the sampling methodology and the particular protocol implemented.
authors.affiliation: Texas A & M University, College Station, TX, USA. balsis@tamu.edu
authors.forename: Steve
authors.initials: S
authors.lastname: Balsis
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Cully
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D003071:Cognition; D003430:Cross-Sectional Studies; D003863:Depression / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008609:Mental Status Schedule; D015995:Prevalence; D012720:Severity of Illness Index; D013405:Suicide / Q000523:psychology; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology