Table 2.

Association between cumulative number of times reported clinical depression diagnosisa at each cycle and invasive breast cancer risk, NHS (2000–2012), and NHSII (2003–2013)

All invasive casesER positiveER negativePostmenopausal at diagnosis
Cases/person-yearsAge- and calendar year adjustedFully adjustedbCases/person-yearsFully adjustedbCases/person-yearsFully adjustedbCases/person-yearsFully adjustedb
NHS (n= 2,667 cases)
 02,400/734,1391 (ref)1 (ref)1,975/734,1391 (ref)302/734,1391 (ref)2,391/734,1271 (ref)
 1219/72,7680.97 (0.84–1.11)0.95 (0.81–1.12)176/72,7680.97 (0.81–1.17)32/72,7680.89 (0.58–1.38)219/72,7680.96 (0.81–1.13)
 239/12,0831.16 (0.84–1.59)1.13 (0.80–1.58)31/12,0831.14 (0.78–1.67)6/12,0831.14 (0.48–2.72)39/12,0831.13 (0.80–1.58)
 3+9/2,5081.49 (0.77–2.88)1.44 (0.73–2.82)5/2,5081.00 (0.41–2.44)3/2,5082.96 (0.89–9.90)9/2,5081.44 (0.74–2.82)
NHS II (n = 1,347 cases)
 01,078/570,3941 (ref)1 (ref)858/570,3941 (ref)178/570,3941 (ref)635/569,4751 (ref)
 1138/73,8150.98 (0.82–1.17)1.04 (0.85–1.28)113/73,8151.05 (0.84–1.31)21/73,8151.06 (0.64–1.76)83/73,7121.00 (0.77–1.29)
 272/38,6370.94 (0.74–1.19)1.00 (0.76–1.31)56/38,6370.94 (0.69–1.27)15/38,6371.51 (0.81–2.79)54/38,6011.08 (0.78–1.48)
 3+59/29,2761.02 (0.78–1.33)1.07 (0.78–1.46)54/29,2761.11 (0.80–1.55)3/29,2760.50 (0.15–1.69)46/29,2521.11 (0.77–1.59)
Pooled (n = 4,014 cases)
 03,478/1,304,5331 (ref)1 (ref)2,833/1,304,5331 (ref)480/1,304,5331 (ref)3026/1,303,6021 (ref)
 1357/146,5830.97 (0.87–1.09)0.99 (0.87–1.12)289/146,5831.01 (0.87–1.16)53/146,5830.96 (0.69–1.33)302/146,4800.97 (0.84–1.11)
 2111/50,7201.01 (0.83–1.24)1.05 (0.85–1.29)87/50,7201.01 (0.80–1.28)21/50,7201.37 (0.83–2.27)93/50,6841.10 (0.87–1.39)
 3+68/31,7841.09 (0.82–1.45)1.13 (0.85–1.49)59/31,7841.10 (0.81–1.50)6/31,7841.22 (0.21–6.99)55/31,7601.18 (0.85–1.62)
  • aClinical depression defined as self-reported of having been diagnosed with depression by a physician or other medical professional.

  • bAdjusted for age, calendar year, BMI, count of antidepressant use, age at menarche, current oral contraceptive use (NHSII only), type of PMH use, age at menopause, age at first birth and parity, history of biopsy-confirmed benign breast disease, family history of breast cancer, mammogram in prior 2 years, smoking status, physical activity, alcohol intake, and AHEI score.