Levonorgestrel intrauterine device and depression: A Swedish register-based cohort study

Abstract

BACKGROUND: The levonorgestrel intrauterine device (LNG-IUD) is traditionally viewed as a safe contraceptive with limited systemic effects. However, three recent studies have indicated an increased risk of depression subsequent to LNG-IUD use. This study aimed to examine the potential associated risk between LNG-IUDs and depression, and determine which women are at risk. METHODS: This longitudinal cohort study was based on data from seven Swedish national population-based registers. All Nordic-born women aged 15-24 years residing in Sweden between 2010 and 2017 were included. Cox regression was implemented to estimate the adjusted hazard ratio (AHR) for developing depression, defined as first depression diagnosis or redeemed prescription for antidepressant treatment. We adjusted for age, education level, parental country of origin, parental psychiatric health, previous hormonal contraceptive use and medical indications for contraceptive use. FINDINGS: 703,157 women were included in the analysis. The LNG-IUD was associated with 57 % increased risk of depression [AHR 1.57 (95 % CI 1.51-1.64)]. The greatest risk increase was seen in adolescent women [AHR 2.57, (95 % CI 2.36-2.80)] and women who used the LNG-IUD as their first hormonal contraceptive method [AHR 1.63, (95 % CI 1.50-1.78)]. The risk of depression decreased at the end of study period [AHR 1.43, (95 % CI 1.36-1.51)], once the LNG-IUD became more widely accessible among nulliparous women. CONCLUSIONS: Adolescent women who use the LNG-IUD as their first-ever hormonal contraceptive are at increased risk of developing depression. However, additional impact from confounding factors is likely as risk estimates decreased over the study period. Further research needs to determine if there is a causal relationship between LNG-IUDs and depression.