Association of Hormonal Contraceptive Use With Reduced Levels of Depressive Symptoms

A National Study of Sexually Active Women in the United States

Katherine M. Keyes; Keely Cheslack-Postava; Carolyn Westhoff; Christine M. Heim; Michelle Haloossim; Kate Walsh; Karestan Koenen

Disclosures

Am J Epidemiol. 2013;178(9):1378-1388. 

In This Article

Results

Differences Between Women Based on Contraceptive Use

Table 1 indicates that contraception-use groups in this sample differed with regard to all covariates studied except for the importance of religion in their lives, lifetime number of sexual partners, and wave 1 and wave 3 suicide attempts. In general, women using hormonal contraceptives were younger than women in other groups, less likely to have children, more likely to have a college degree, more likely to engage in individual sports (e.g., running), more likely to engage in positive health behaviors such as undergoing a routine physician's checkup and visiting the dentist, less likely to be a regular smoker, and more likely to have used hormonal contraception in the past. Women using hormonal contraceptives also had a lower mean body mass index than other groups and a lower depression score in each prior interview.

Using these covariates as well as design variables, we created a propensity score using a binary indicator of hormonal contraceptive use versus none as the outcome. Figure 2 shows the distribution of propensity scores in users and nonusers of hormonal contraceptives. Table 2 shows the percentage of women in each contraception-use category in each quintile of the propensity score; for example, 74.5% of women with the highest propensity to use hormonal birth control (propensity score >0.83) actually used hormonal birth control, and 10.4% of women with the lowest propensity to use hormonal birth control (propensity score <0.39) actually used hormonal birth control. The smallest cell size was the number of women with a propensity score greater than 0.83 who used highly effective birth control (n = 34), and cell sizes for the remainder of the contraception categories in the >0.83 category were substantially larger. The mean cell size across all propensity score quintiles and contraception categories was 202 women. Given the sufficient sample size in each of these cells, we used propensity score as a control variable in the regression modeling described below.

Figure 2.

Distribution of propensity scores among users (A) and nonusers (B) of hormonal birth control aged 25–34 years in a nationally representative sample of sexually active nonpregnant US women, National Longitudinal Study of Adolescent Health, 2007–2008.

Association Between Hormonal Contraceptive Use and Depression and Suicide Attempts

When adjusted for propensity score, hormonal contraceptive users had lower mean levels of past-week depressive symptoms (β = −1.04, 95% confidence interval (CI): −1.73, −0.35), lower odds of high levels of depressive symptoms (odds ratio (OR) = 0.68, 95% CI: 0.49, 0.94), and lower odds of past-year suicide attempts (OR = 0.37, 95% CI: 0.14, 0.95). These results held when we adjusted for propensity score as a continuous variable (Table 3), a 5-level categorical quintile variable (results not shown), or a subset within each quintile (direction and magnitude were the same, although power was reduced in some quintiles; results not shown).

Results were similar when covariates were controlled in the regression rather than propensity score (Table 3), although the confidence interval for hormonal contraceptive users was wide for high depression levels (OR = 0.81, 95% CI: 0.58, 1.14).

Users of Progestin-only Hormonal Contraceptives

We analyzed the 298 women using hormonal contraceptive formulations that are known to contain progestin only (i.e., Depo-Provera or Norplant) separately from women using other hormonal contraceptives. In fully controlled models, women using progestin-only contraception had significantly lower levels of depressive symptoms than women using the lowest-efficacy contraceptives or no contraceptives (β = −1.3, 95% CI: −2.4, −0.2). Results were consistently protective for high levels of depressive symptoms, although the finding was not significant (OR = 0.7, 95% CI: 0.4, 1.2), and results were not significant or protective for suicide attempts (OR = 1.6, 95% CI: 0.4, 6.1). Women using progestin-only contraceptives did not have significantly different levels of depression symptoms than women using other forms of hormonal contraception (β = −0.3, 95% CI −1.2, 0.6).

Longitudinal Associations Between Hormonal Contraceptive Use and Depression

In Figure 3, we dichotomize contraceptive users into women using hormonal contraceptives (pill, patch, ring, or progestin-only) and all other women, and we show all associations between hormonal contraceptive use and high depression scores across 2 waves of data. There were protective associations between hormonal contraceptive use and high depression scores when both were measured at the wave 3 interview (ages 18–28 years) (OR = 0.76, 95% CI: 0.57, 1.02) and when both were measured at the wave 4 interview (ages 25–34 years) (OR = 0.83, 95% CI: 0.63, 0.98).

Figure 3.

Adjusted odds ratios (ORs) for the association between hormonal contraceptive (HC) use and past-week high depression score (Dep) among nonpregnant women aged 18–34 years with a current sex partner in 2 study waves, National Longitudinal Study of Adolescent Health, 2001–2008. For OR = 0.76, P = 0.06; for OR = 3.72, OR = 0.83, and OR = 2.08, P < 0.05. Wave 3 logistic regression analyses adjusted for race/ethnicity, wave 3 education, age, parity, past-year monogamy, lifetime number of vaginal sex partners, importance of religion, regular engagement in an individual sport (e.g., running or jogging), body mass index, visiting a dentist in the last 2 years, smoking, wave 1 or 2 highest depression score, and wave 1 or 2 use of hormonal birth control. Wave 4 logistic regression analyses adjusted for race/ethnicity and wave 4 age, education, smoking, parity, past-year monogamy, lifetime number of vaginal sex partners, importance of religion, regular engagement in an individual sport (e.g., running or jogging), body mass index, visiting a dentist in the last 2 years, undergoing a routine checkup by a physician in the last 2 years, wave 1, 2, or 3 high depression, and wave 1, 2, or 3 use of hormonal birth control. A high depression score was defined as a score greater than or equal to 11 on the 10-item Center for Epidemiologic Studies Depression Scale.

We then repeated this longitudinal analysis with past-year suicide attempts as the outcome (Figure 4). While hormonal contraceptive use was not protective against suicide attempts at the wave 3 interview (ages 18–28 years), it was protective against suicide attempts at the wave 4 interview (ages 25–34 years) (OR = 0.31, 95% CI: 0.15, 0.66).

Figure 4.

Adjusted odds ratios (ORs) for the association between hormonal contraceptive (HC) use and past-year suicide attempts (SA) among nonpregnant women aged 18–34 years with a current sex partner in 2 study waves, National Longitudinal Study of Adolescent Health, 2001–2008. For OR = 9.30, OR = 0.31, and OR = 2.00, P < 0.05. Wave 3 logistic regression analyses adjusted for race/ethnicity, wave 3 education, age, parity, past-year monogamy, lifetime number of vaginal sex partners, importance of religion, regular engagement in an individual sport (e.g., running or jogging), body mass index, visiting a dentist in the last 2 years, smoking, wave 1 or 2 suicide attempts, and wave 1 or 2 use of hormonal birth control. Wave 4 logistic regression analyses adjusted for race/ethnicity and wave 4 age, education, smoking, parity, past-year monogamy, lifetime number of vaginal sex partners, importance of religion, regular engagement in an individual sport (e.g., running or jogging), body mass index, visiting a dentist in the last 2 years, undergoing a routine checkup by a physician in the last 2 years, wave 1, 2, or 3 suicide attempts, and wave 1, 2, or 3 use of hormonal birth control. A high depression score was defined as a score greater than or equal to 11 on the 10-item Center for Epidemiologic Studies Depression Scale.

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