Relationship between diagnostic criteria, depressive equivalents and diagnosis of depression among older adults with intellectual disability.
BACKGROUND
Depression is more common among persons with an intellectual disability (ID) than the general population, and may be expected to increase with age just as in the general population. However, little is known about depression among older adults with ID. The literature has questioned the use of standard diagnostic criteria for depression among both older adults and persons with ID, and behavioural depressive equivalents have been suggested. This study uses the interRAI ID assessment instrument to investigate the relationship between standard diagnostic criteria for depression, depressive equivalents and a diagnosis of depression among older and younger adults with ID in community and institutional settings in Ontario, Canada.


METHODS
Items in the interRAI ID assessment instrument that were representative of The Diagnostic and Statistical Manual of Mental Disorders 4th Edition (DSM-IV) criteria and depressive equivalents were examined among persons with ID in institutional (census-level data) and in community-based (sample) residential settings. Bivariate logistic regression was used to examine the relationship between depressive symptoms and a diagnosis of depression. Descriptive statistics were used to examine the prevalence of depressive symptoms among those who did not have a diagnosis of depression.


RESULTS
The results indicate that DSM-IV diagnostic criteria and depressive equivalents were significantly related to a diagnosis of depression among older and younger adults with ID, and that both types of symptoms were exhibited by a non-trivial proportion of individuals without a diagnosis of depression.


CONCLUSIONS
The depression rating scale embedded in the interRAI ID is helpful in identifying older adults at risk of depression. Contrary to other studies, few significant differences were found in depressive symptoms by age.
Langlois
L
L
Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada.
Martin
L
L
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000375:Aging / Q000523:psychology*; D002170:Canada / Q000453:epidemiology; D015897:Comorbidity; D003866:Depressive Disorder / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D005260:Female; D006801:Humans; D007326:Institutionalization / Q000706:statistics & numerical data; D008607:Intellectual Disability / Q000453:epidemiology / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012111:Residence Characteristics; D012720:Severity of Illness Index; D055815:Young Adult