Figure 1

Incident users of antidepressants before and after diagnosis of cancer among all 849 colorectal cancer patients diagnosed in 1998–2009. To exclude prevalent users of antidepressants the third year before cancer (−3) was used as a wash-in period. The second year before cancer (−2) is thus the first year in which we observe incident use of antidepressants. The incidence was calculated as number of new users divided by the total number of days (converted to years) contributed to each time period. All individuals were followed for first redeemed prescription of an antidepressant and, until emigration, new diagnosis of cancer (except non-melanoma skin cancer), diagnosis of a psychiatric disorders to which depression could be considered secondary (ICD-8: 290–295.99, 296.19, 296.39, 303.00–304.99 and ICD-10: F00–F31), death or 5 years after diagnosis of colorectal cancer, whichever came first. ICD-8, International Classification of Disease 8.