'The Pill' is a revolutionary drug that has changed the lives of millions the world over.
Not only can the right combination of progesterone and estrogen prevent pregnancy with great effectiveness, but it can also be used to treat acne, menstrual pain, migraines, and symptoms of endometriosis.
Like any medication, however, oral contraceptive pills come with risks and side effects that vary from person to person – and depression seems to be one of them.
A recent observational study, based on 264,557 people in the United Kingdom Biobank, has found further evidence that the combined oral contraceptive is associated with "an increased risk of depression shortly after initiation."
The research was conducted by scientists from Uppsala University in Sweden, the University of Melbourne in Australia, and the University of Copenhagen in Denmark, and while it does not prove causation, the results are worth considering further.
Compared to those participants who had never taken a combined oral contraceptive in their life, the researchers found those who started taking oral contraceptives faced an 80 percent increased risk of being diagnosed with depression in the first two years.
Of all the age groups represented in the cohort, teenage patients seemed the most susceptible. In the first two years of oral contraceptive use, people under 20 years of age faced a 95 percent increased risk of depression.
The findings are significant, but they should not frighten people away from taking oral contraceptives. These medicines help many and are highly effective at what they do.
That said, it's important that both physicians and patients are aware of any serious side effects that could possibly arise in those first few years.
If the risk of depression does exist, it appears to drop off over time. In the Biobank study, the lifetime risk of depression among those who took contraceptive pills was only 5 percent greater than the control group.
"[Psychiatrists] should consider discussing this potential risk with their patients and closely monitor any changes in mood or mental well-being during contraceptive use," drug researcher Therese Johansson from Uppsala told Terri D'Arrigo from Psychiatric News.
"This study underscores the need for continued research and dialogue in this area, with the ultimate goal of providing better care and support to women in managing their reproductive health while safeguarding their mental well-being."
Negative mood and depression are two of the most common side effects reported by users of hormonal contraceptives. Historically, however, the link between the Pill and mood disorders has remained "inadequately addressed", according to Johansson and her colleagues.
While it's true that several large, observational studies in Denmark and Sweden have also found associations between hormonal contraception and the risk of depression in adolescents, randomized clinical trials have not revealed a clear causative link.
Part of the problem may be that patients who suffer from mood disturbances withdraw from these studies at higher rates.
To provide more clarity on the topic, an international team of researchers, led by Johansson and her colleagues at Uppsala, analyzed the mental health data from a subcohort of 82,232 women in the UK Biobank.
In this additional analysis, the authors found that those who had used oral contraceptives faced twice the risk of depression in the first two years of initiating the meds compared to those who had never used them.
Adolescents, by comparison, faced a 130 percent higher risk of depressive symptoms during those first two years.
In adulthood, the authors note, women have already gone through substantial hormonal changes, which could be part of the reason why oral contraceptives don't seem to impact them nearly as much.
Other researchers, however, argue that this stronger effect in younger women could be explained by the "higher proportion of first-time users, not by younger age itself."
Further research is needed to understand if hormonal contraception influences a person's mood in a causative way and how its impact might change before and after puberty.
"Since we only investigated combined contraceptive pills in this study, we cannot draw conclusions about other contraceptive options, such as mini pills, contraceptive patches, hormonal spirals, vaginal rings or contraceptive rods," Johansson says.
She and her colleagues aim to provide more information on these other forms in the future, so patients can make well-informed decisions about their contraceptive options.
The study was published in Epidemiology and Psychiatric Sciences.