Investigators from Uppsala University, Uppsala, Sweden, and Karolinska Institute, Stockholm, Sweden, conducted a retrospective cohort study to determine if young women with attention-deficit hyperactivity disorder (ADHD) are more likely to develop depression when using hormonal contraceptives (HC) than those without this diagnosis. For the study, they used data included in multiple Swedish national registries, such as the Swedish Prescribed Drug Registry (PDR), National Patient Register (NPR), Total Population Registry, Multi-Generational Registry, and Education Register. Swedish personal identity numbers were used to link data between registries. Study participants were young women who were 15-24 years old at any time between 2010 and 2017. Participants were classified as having ADHD if they had ever been diagnosed with this disorder (based on ICD codes in the NPR) or been treated with an ADHD medication (based on Anatomic Therapeutic Chemical [ATC] codes in the NPR). Use of HC also was determined using ATC codes and was categorized as combined oral contraception (COC), progestogen-only pill (POP), or non-oral (intrauterine device, contraceptive patch, or injection). The primary study outcome was depression, which was defined using ICD codes and/or ATC codes for depression medications. Young women with depression diagnosed prior to the study start were excluded. Cox hazard regression was used to identify risk factors for depression after controlling for multiple con-founders, including age, educational level, and parent history of mental illness. An ADHD x HC interaction term was included in the model. Subgroup analyses were also performed.
Data were analyzed on 29,767 young women with ADHD (3.8%) and 763,146 without this diagnosis. Participants with ADHD were significantly younger, less educated, and more likely to have a parental history of mental illness than those without ADHD. Among young women with ADHD, 41.9% developed depression compared to 10.5% of those without ADHD (adjusted hazard ratio [aHR], 3.69; 95% CI, 3.60, 3.78). When considering all study participants, HC use was not associated with developing depression (aHR, 0.99; 95% CI, 0.97, 1.00). However, there was a significant interaction between ADHD diagnosis and HC use on risk of developing depression (aHR, 1.39; 95% CI, 1.33, 1.45). A significant effect between ADHD and HC on developing depression was observed for COC and POP but not non-oral hormonal contraception. Among young women with ADHD using COC, the risk of depression was significantly greater compared to those without ADHD who were not using COC (aHR, 5.19; 95% CI, 4.95, 5.47). Similarly, those with ADHD using POP were more likely to develop depression than young women without ADHD who weren’t using POP (aHR, 5.00; 95% CI, 4.56, 5.49).
The authors conclude that young women with ADHD using oral contraceptives are at increased risk for developing depression.
Dr Raphael has disclosed no financial relationship relevant to this commentary....