Increased incidence of affective disorders, anxiety disorders, and non-natural mortality in women after breast cancer diagnosis: a nation-wide cohort study in Denmark.

OBJECTIVE: To investigate whether breast cancer patients have increased incidence of psychiatric admission with affective disorders, anxiety disorders, or non-natural mortality compared with the general female population. METHOD: Register-linkage between nation-wide registries: The Danish Psychiatric Central Register, The Danish Cancer Registry, and The Danish National Register of Causes of Death. A total of 61 709 women registered with primary invasive breast cancer between 1970 and 1993 were included and 356 023 person-years were accrued. RESULTS: The standardized incidence ratio of first-ever psychiatric admission with affective disorder was 1.49 (95% CI: 1.35-1.63) and with anxiety disorder 1.25 (95% CI: 1.06-1.46). The standardized non-natural mortality ratio during the first year after breast cancer diagnosis was 1.54 (95% CI: 1.27-1.87). All analyses were adjusted for age, calendar period, and place of residence. CONCLUSION: Breast cancer patients have significantly increased incidence of psychiatric admission with affective disorders, anxiety disorders, and non-natural mortality.

Breast cancer risk among women with psychiatric admission with affective or neurotic disorders: a nationwide cohort study in Denmark.

There is a considerable interest in the possible relationship between psychosocial factors and the onset of breast cancer. This cohort study was based upon two nationwide and population-based central registers: The Danish Psychiatric Central Register, which contains all cases of psychiatric admissions, and The Danish Cancer Registry, which contains all cases of cancer. The register-linkage was accomplished by using a personal identification number. The study population comprised all women admitted to psychiatric departments or psychiatric hospitals in Denmark between 1969 and 1993 with an affective or a neurotic disorder. Overall, 66,648 women comprising 199,910 admissions and 775,522 person-years were included. The incidence of breast cancer in the cohort was compared with the national breast cancer incidence rates adjusted for age and calendar time. In all, 1270 women with affective or neurotic disorders developed breast cancer subsequent to the first admission as compared with the 1242 women expected, standardized incidence ratio (SIR) = 1.02 (95% confidence interval 0.97-1.08). None of the hypothetical risk factors: type of diagnosis, age or calendar period at cohort entry, age at breast cancer, alcohol abuse, alcohol/drug abuse without further specification, total number of admissions, total length of admissions, or time from first admission showed a statistically significant effect on the relative risk of breast cancer. We found no support for the hypothesis that women admitted to a psychiatric department with an affective or a neurotic disorder subsequently have an increased risk of breast cancer.