An article on The Sun’s website features the headline: “Taking the Pill could ‘save your life’ as fewer women attempt suicide, experts say”.
This headline is not an accurate representation of the (as yet unpublished) research cited in the article, which reports on a study looking at possible links between hormonal contraceptives and suicide, and did not claim a causal relationship between the two.
Despite the phrase “save your life” appearing in the headline as if it was said by an expert, the article itself does not attribute the phrase to anyone in particular. Dr Elena Toffol, lead researcher on the study, told Full Fact the headline was an exaggeration of its findings and was not a quote from her.
Correlation is not causation
The study, which was presented to the European Psychiatric Association but has not yet been published, used data on more than half a million women in Finland aged between 15-49 to compare attempted suicide rates among those who used hormonal contraceptives to those who did not.
The study’s definition of hormonal contraception did not solely refer to the contraceptive pill, as suggested by The Sun’s headline, but also other methods of contraception, including the implant and the intrauterine system (IUS).
It found 344 cases of suicide attempts among women who had redeemed a prescription for hormonal contraceptives in 2017, and 474 cases of suicide attempts in women who did not. It therefore concluded that in Finland, women who did not use hormonal contraceptives were 37% more likely to attempt suicide in the following two years than women who did.
While this study did find an association between hormonal contraceptive prescriptions and lower rates of attempted suicide, it does not show that the contraceptive pill is the cause of this reduced the risk of suicide or that it “saves lives” by cutting the rate of suicide attempts among women as The Sun suggests.
It was not intended to prove causality between the contraceptive pill and lower risk of suicide. In a presentation at the European Congress of Psychiatry, Dr Toffol said that she had instead set out to verify previous data suggesting that hormonal contraception was plausibly linked to higher risk of suicide. Dr Toffol told Full Fact that instead their data suggested using hormonal contraception seems not to be associated with increased odds of attempted suicide.
When trying to determine whether one factor caused a certain result, it is important to control for all other factors that may influence the findings. Dr Toffol confirmed the study did control for a range of risk factors, including psychiatric history, marital status, socioeconomic status, education, chronic diseases and use of psychotropic medications.
She said that the study’s analysis showed that hormonal contraceptives were not associated with any increased risk of attempted suicide for women with a psychiatric history, and were associated with a lower risk for women with no history of attempted suicide.
It did not, however, conclude whether contraceptive use was the reason for the lower risk of suicide.
Study not yet published
As the research hasn’t been fully published yet it is hard to assess its methodological qualities and limits fully.
However, one potential issue that affects how the findings are interpreted is how the study categorised contraceptive users and non-users. Dr Toffol told Full Fact that the control group of non-users included women who had not been prescribed hormonal contraception in 2017, or had been prescribed hormonal contraception but not redeemed it.
But that means some of the control group of non-users may have had a history of contraceptive use prior to 2017, which could obscure the association between contraceptive use and the risk of suicide. Some previous major studies looking into the relationship between hormonal contraceptives and suicide analysed data from a much longer period of time.
Dr Toffol told Full Fact this was because “information on redeemed prescriptions of hormonal contraception were not available in Finland before 2017.”
The research compared the rate of suicide between women who “redeemed prescriptions” for contraception with those who didn’t, but it’s unclear whether all of these women who redeemed a prescription went on to use the contraception, or used it correctly, or how long they used it for.
However, Dr Toffol also said the study included a wider age range than previous studies.
Professor Andrea Fiorillo, editor in chief of the European Psychiatry journal, said: “This striking finding deserves a careful evaluation and needs to be replicated in different cohorts of women and controlled for the impact of several psychosocial stressors, such as economic upheavals, social insecurity and uncertainty due to the COVID pandemic. The clinical implications of the study are obvious and may help to destigmatize the use of hormonal contraceptives.”
Image courtesy of Reproductive Health Supplies Coalition