Depression and cancer risk: a register-based study of patients hospitalized with affective disorders, Denmark, 1969-1993.
The authors investigated the cancer risk of patients hospitalized for depression in a nationwide Danish cohort study. All 89,491 adults in Denmark who had been admitted to a hospital with depression, as defined in the International Classification of Diseases, Eighth Revision, between 1969 and 1993 were identified. There were 1,117,006 person-years of follow-up. Incidence rates of all cancers and of site-specific cancers were compared with national incidence rates for first primary cancers, with data being adjusted for sex, age, and calendar time. A total of 9,922 cases of cancer were diagnosed in the cohort, with 9,434.6 having been expected; this yielded a standardized incidence ratio of 1.05 (95% confidence interval (CI): 1.03, 1.07). The risk of cancer was increased for the first year after hospital admission, with brain cancer especially occurring more frequently than expected. When the first year of follow-up was excluded, the increase was attributable mainly to an increased risk of tobacco-related cancers: Standardized incidence ratios for non-tobacco-related cancers were 1.00 (95% CI: 0.97, 1.03) after 1-9 years of follow-up and 0.99 (95% CI: 0.95, 1.02) after 10 or more years of follow-up. These data provide no support for the hypothesis that depression independently increases risk of cancer, but they emphasize the deleterious effect that depression can have on lifestyle factors.
Dalton
Susanne Oksbjerg
SO
Danish Cancer Society, Institute of Cancer Epidemiology, DK-2100 Copenhagen, Denmark. sanne@cancer.dk
Mellemkjaer
Lene
L
Olsen
Jørgen H
JH
Mortensen
Preben B
PB
Johansen
Christoffer
C
D000328:Adult; D000341:Affective Disorders, Psychotic / Q000150:complications / Q000453:epidemiology*; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology* / Q000209:etiology; D012042:Registries; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects