Importance: The repercussions of abortion for mental health have been used to justify state policies that limit access to abortion in the United States. Much earlier research has relied on self-report of abortion or mental health conditions or on convenience samples. This study uses data that rely on neither.
Objective: To examine whether first-trimester first abortion or first childbirth is associated with an increase in women's initiation of a first-time prescription for an antidepressant.
Design, setting, and participants: This study linked data and identified a cohort of women from Danish population registries who were born in Denmark between January 1, 1980, and December 30, 1994. Overall, 396 397 women were included in this study; of these women, 30 834 had a first-trimester first abortion and 85 592 had a first childbirth.
Main outcomes and measure: First-time antidepressant prescription redemptions were determined and used as indication of an episode of depression or anxiety, and incident rate ratios (IRRs) were calculated comparing women who had an abortion vs women who did not have an abortion and women who had a childbirth vs women who did not have a childbirth.
Results: Of 396 397 women whose data were analyzed, 17 294 (4.4%) had a record of at least 1 first-trimester abortion and no children, 72 052 (18.2%) had at least 1 childbirth and no abortions, 13 540 (3.4%) had at least 1 abortion and 1 childbirth, and 293 511 (74.1%) had neither an abortion nor a childbirth. A total of 59 465 (15.0%) had a record of first antidepressant use. In the basic and fully adjusted models, relative to women who had not had an abortion, women who had a first abortion had a higher risk of first-time antidepressant use. However, the fully adjusted IRRs that compared women who had an abortion with women who did not have an abortion were not statistically different in the year before the abortion (IRR, 1.46; 95% CI, 1.38-1.54) and the year after the abortion (IRR, 1.54; 95% CI, 1.45-1.62) (P = .10) and decreased as time from the abortion increased (1-5 years: IRR, 1.24; 95% CI, 1.19-1.29; >5 years: IRR, 1.12; 95% CI, 1.05-1.18). The fully adjusted IRRs that compared women who gave birth with women who did not give birth were lower in the year before childbirth (IRR, 0.47; 95% CI, 0.43-0.50) compared with the year after childbirth (IRR, 0.93; 95% CI, 0.88-0.98) (P < .001) and increased as time from the childbirth increased (1-5 years: IRR, 1.52; 95% CI, 1.47-1.56; >5 years: IRR, 1.99; 95% CI, 1.91-2.09). Across all women in the sample, the strongest risk factors associated with antidepressant use in the fully adjusted model were having a previous psychiatric contact (IRR, 3.70; 95% CI, 3.62-3.78), having previously obtained an antianxiety medication (IRR, 3.03; 95% CI, 2.99-3.10), and having previously obtained antipsychotic medication (IRR, 1.88; 95% CI, 1.81-1.96).
Conclusions and relevance: Women who have abortions are more likely to use antidepressants compared with women who do not have abortions. However, additional aforementioned findings from this study support the conclusion that increased use of antidepressants is not attributable to having had an abortion but to differences in risk factors for depression. Thus, policies based on the notion that abortion harms women's mental health may be misinformed.