Table 3.

Association between cumulative number of times reported severe depressive symptomsa 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)
 02,301/760,2691 (ref)1 (ref)2,028/760,2691 (ref)313/760,2691 (ref)2,461/751,8891 (ref)
 1137/45,5870.93 (0.78–1.10)0.91 (0.77–1.09)109/45,5870.90 (0.74–1.09)21/45,5871.05 (0.67–1.65)137/45,5870.92 (0.77–1.09)
 239/14,8870.79 (0.58–1.09)0.79 (0.57–1.09)31/14,8870.79 (0.55–1.13)7/14,8871.02 (0.48–2.20)39/14,8870.79 (0.58–1.09)
 3+20/8,3940.74 (0.48–1.15)0.76 (0.48–1.18)18/8,3940.89 (0.55–1.42)2/8,3940.51 (0.12–2.06)20/8,3940.76 (0.49–1.19)
NHS II (n= 1,347 cases)
 01,089/557,0351 (ref)1 (ref)873/557,0351 (ref)178/557,0351 (ref)661/556,1461 (ref)
 1125/73,5820.87 (0.73–1.05)0.88 (0.73–1.06)102/73,5820.89 (0.72–1.09)18/73,5820.81 (0.49–1.32)74/73,4960.83 (0.65–1.06)
 258/28,2541.04 (0.80–1.36)1.11 (0.85–1.45)53/28,2541.24 (0.94–1.65)3/28,2540.39 (0.12–1.22)37/28,2101.08 (0.77–1.52)
 3+22/12,9140.86 (0.57–1.31)0.97 (0.63–1.48)15/12,9140.81 (0.48–1.35)7/12,9142.18 (1.00–4.71)15/12,9011.01 (0.60–1.70)
Pooled (n= 4,014 cases)
 03,390/1,317,3041 (ref)1 (ref)2,901/1,317,3041 (ref)491/1,317,3041 (ref)3,122/1,308,0351 (ref)
 1262/119,1690.90 (0.79–1.02)0.90 (0.79–1.02)211/119,1690.89 (0.77–1.03)39/119,1690.93 (0.67–1.30)211/119,0830.89 (0.77–1.02)
 297/43,1410.92 (0.71–1.21)0.95 (0.68–1.32)84/43,1411.01 (0.65–1.56)10/43,1410.69 (0.27–1.77)76/43,0970.92 (0.68–1.25)
 3+42/21,3080.80 (0.59–1.09)0.86 (0.63–1.17)33/21,3080.85 (0.60–1.20)9/21,3081.19 (0.29–4.85)35/21,2950.86 (0.61–1.20)
  • aSevere depressive symptoms defined as a score ≤52 on the MHI-5 scale.

  • 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.