Mohammed T. Abou-Saleh

392 PRINCIPLES AND PRACTICE OF GERIATRIC PSYCHIATRY25. Myers JK, Weissman MM, Tischler GL et al. Six-month prevalenceof psychiatric disorders in three communities. Arch Gen Psychiat1984; 41: 959–70.26. Blazer DG, Bachar JR, Manton KG. Suicide in late life: review andcommentary. J Am Geriat Soc 1986; 34: 519–25.27. Jensen K. Psychiatric problems in four Danish old age homes. ActaPsychiat Scand 1966; 169 (suppl): 411–18.28. Copeland JRM, Beekman ATF, Dewey ME et al. Depression inEurope: geographical distribution among older people. Br J Psychiat1999; 174: 312–29.29. Kua EH. Depressive disorder in elderly Chinese people. Acta PsychiatScand 1990; 81: 386–8.Epidemiological Catchment Area Studies of Mood DisordersDan G. BlazerDuke University Medical Center, Durham, MC, USAThe National Institute of Mental Health Multi-site EpidemiologicCatchment Area (ECA) 1 Program consists of a combinedcommunity and institutional survey of five communities in theUSA: New Haven, Connecticut; Baltimore, Maryland; Durham,North Carolina; St Louis, Missouri and Los Angeles, California.Because of the large sample drawn for this study and becauseoversamples of the elderly were drawn at three sites, data areavailable that permit the estimate of the prevalence of affectivedisorders from a larger sample of community-dwelling elders thanfrom any other extant study.The goals of the Epidemiologic Catchment Area Program wereto: (a) estimate the prevalence of specific psychiatric disordersusing a similar methodology across multiple geographic samplingareas; (b) determine correlates of these specific psychiatricdisorders; and (c) determine the relationship between psychiatricdisorders and health services utilization.The 6-month prevalence of the affective disorders from the fiveECA sites overall range from 4% to 7% 2 . All affective disorders,except for bereavement, were less prevalent in the elderly than atother stages of the life cycle. For example, the prevalence of majordepression in men ranged between 1% and 4% among the 18–24year-olds but was consistently less than 1% in the 65 age group.Among 18–24 year-old women, the prevalence of major depressionwas 7%, whereas in women in the 65+ age group it did notexceed 3% at any of the ECA sites. Recent incidence studies fromthe ECA sample suggest that the incidence for major depressionpeaks in the 30s with a smaller peak during the 50s. Incidence ismuch lower for the elderly.Dysthymic disorder varied less by age in prevalence than majordepression and was more prevalent than major depression in theelderly 3 . For example, the prevalence of dysthymic disorder was0.5–3% in 18–24 year-old men and 0.5–2% in 65 year-old men.Among women, dysthymic disorder was 1–4% in 18–24 year-oldwomen and between 1–4% in 65+ year-old women. Overall, currentaffective disorders of all types were less frequent in older persons(65+ years of age) than for any other age group. Manic disorderswere extremely rare in the sample overall (0.5–1%). No cases ofmaniawereidentifiedinthe65+agegroupacrossthefiveECAsites.The lifetime prevalence rates for the DSM-III specificpsychiatric disorders evaluated in the ECA sample paralleledrates of current prevalence but, as would be expected, werehigher 3 . Lifetime prevalence for major depression was 4–10% inthe 25–44 age group but was not higher than 2% in the 65+ agegroup at any ECA site. Only one lifetime occurrence of manicepisode was identified in this very large sample.The ECA studies have received considerable criticism fromgeriatric psychiatrists who perceive that the study design significantlyunderestimates the prevalence of affective disorders in olderadults. The dramatic differences in prevalence (both current andlifetime) by age surely calls for some explanation. Studies areemerging to suggest that the Diagnostic Interview Schedule, theinstrument used to determine the prevalence of psychiatric disordersin the ECA sample, may possibly be biased toward underestimatingthe prevalence of affective disorders in older persons. Specifically,the threshold for a symptom being identified by the instrument maybe increased for older persons. Nevertheless, the threshold effectdoes not appear to explain the dramatic differences in prevalenceand has led a number of investigators to suspect that a cohortphenomenon is operative 5 . That is, older persons not only havelower current prevalence of depression in the 1990s, they havealways experienced a lower prevalence. According to a number ofstudies, this is true among more modern, Western societies.REFERENCES1. Regier DA, Myers JK, Kramer M et al. The NIMH EpidemiologicCatchment Area Program. Arch Gen Psychiat 1984; 41: 934–41.2. Myers JK, Weissman MM, Tischler GL et al. Six-month prevalence ofpsychiatric disorders in three communities. Arch Gen Psychiat 1984; 41:959–70.3. Robins LN, Helzer JE, Weissman MM. Lifetime prevalence of specificpsychiatric disorders in three sites. Arch Gen Psychiat 1984; 41: 949–58.4. Klerman GL, Weissman MM. Increasing rates of depression. JAmMed Assoc 1989; 261: 229–35.5. Blazer, DG, Bachar JR, Manton KG. Suicide in late life: review andcommentary. J Am Geriat Soc 1986; 34: 519–25.6. Eaton WW, Anthony JC, Gallo J et al. Natural history of DiagnosticInterview Schedule/DSM-IV major depression. The BaltimoreCatchment Area Follow-up. Arch Gen Psychiat 1997; 54: 989–99.