Objectives: To assess 1-week prevalence of International Classification of Disease, Tenth Edition (ICD-10) current depression, physical comorbidity, associated disability, and healthcare utilization in older primary care patients. Comparisons with younger patients are also reported.
Design: Cross-sectional, two-phase epidemiological study.
Setting: One hundred ninety-one primary care clinics.
Participants: Six hundred six patients aged 60 and older and 1,290 patients aged 14 to 59.
Measurements: Screening was conducted using the General Health Questionnaire-12. Probable cases were assessed by primary care physicians (PCPs) with the World Health Organization ICD-10 Checklist for depression to diagnose ICD-10 current depression and subsyndromal depression. Other instruments included the Brief Disability Questionnaire and the PCPs' rating of the severity of physical illness.
Results: The prevalence of current depression was 8.6%; 3.6% for subsyndromal depression (8.3% and 5.5%, respectively, in younger subjects). Current depression was associated with physical illness, physical disability, days lost from work or days unable to perform activities of daily living, and frequency of PCP consultation. Both physical illness and current depression independently resulted in increased disability, and, when the two conditions coexisted, there was a further increase in disability. Comorbidity with physical illness was the hallmark of late-life depression, distinguishing this condition from depression in younger patients. Moreover, depressed older patients were more disabled and had a higher frequency of PCP consultation than younger depressed patients.
Conclusion: The prevalence of current depression does not decrease with age in primary care, in contrast to that seen in community studies. Late-life depression is characterized by physical comorbidity and associated with significant disability. The specific features of late-life depression call for intervention programs taking into account the relationship between the mental, physical, and functional aspects of this condition.