Background. Due to the limited data available, it is not clear whether the
incidence of first-onset depression varies with age in the elderly.
Methods. A representative sample of individuals born 1901-2 (N = 392) was e
xamined at the ages of 70, 75, 79, 81, 83 and 85 years by psychiatrists usi
ng a semi-structured schedule. Information on depressive episodes was also
collected from self-report and examination of case records. Depression was
diagnosed according to the DSM-III-R criteria.
Results. The incidence of depression was 12 per 1000 person-years in men an
d 30 per 1000 person-years in women between the ages of 70 and 85 (sex diff
erence P = 0.001). The incidence increased from 17 per 1000 person-years (m
en 8.7, women 23.2, P = 0.007) between the ages of 70 and 79 to 44 per 1000
person years (men 27.0, women 52.8, P = 0.166) between 79 and 85 (age diff
erence: RR 2.6, P < 0.001; men RR 3.1, P = 0.036; women RR 2.3, P = 0.003).
A diagnosis of depression was associated with increased mortality and refu
sal rate during the 15-year follow-up. Previous episodes of depression were
associated with an increased risk of further episodes. The prevalence of d
epression increased from 5.6% at the age of 70 to 13.0% at the age of 85. T
he lifetime prevalence of depression was 23% in men and 45% in women.
Conclusions. Both the incidence and prevalence of depression increased with
age in this longitudinally followed birth cohort, and the incidence was hi
gher in women than in men.