We ought to be sceptical about the pill’s apparent link with depression

    4 October 2016

    Women who take hormonal contraceptives including the pill have an increased risk of depression, according to research published in the journal JAMA Psychiatry (see our expert analysis below).

    The researchers, from the University of Copenhagen in Denmark, suggested that the hormone progesterone (which is present in most common forms of birth control) had a ‘noticeable effect’ on a person’s mood.

    Teenagers are particularly affected. The researchers found that the likelihood of being prescribed antidepressants increased up to 80 per cent in girls between the ages of 15 and 19 when they took contraceptives.

    The researchers looked at data that tracked all prescriptions and diagnoses in the female population of Denmark between the ages of 15 and 34, giving them a cohort of 1,061,997 women in total.

    They estimated that 55 per cent of participants were currently or had recently been using hormonal contraception. In this group the chance of a diagnosis of depression was 20 per cent higher.

    Women on the pill are, on average, 23 per cent more likely to have antidepressants prescribed. For the mini pill the risk increases to 34 percent.

    The study failed to establish causation, meaning that there is no biological evidence to show that the pill causes depression.

    Instant analysis
    The Danish Sex Hormone Register study is a large cohort study involving all women living in Denmark, which makes for excellent recruitment of numbers with over a million women involved.

    The average age of women in the study was 24; the use of hormonal contraception, which ranges from the simple progesterone-only pill, combined contraceptives, patch, ring, implant and hormone-releasing IUCD (intrauterine contraceptive device), was associated with a higher risk of depression — defined as a diagnosis or a need for antidepressants.

    The highest increase in risk (double the risk) was seen for the implant and injectable (depo); lower increased risk was seen for the other modalities, ranging from an increase in risk between 20-40 per cent. It should be clarified that this risk increase is not the same as saying that 20 to 40 per cent will experience depression.

    A cohort study will only ever establish association and not causation. Questions raised by this study are numerous. How rigorous was the depression diagnosis and how strictly were the diagnostic criteria applied? Was medication prescribed as a first line? What were the socioeconomic circumstances of the patients concerned?

    The age group surveyed here happens to be an age group where increased depression diagnoses are already being made. Studies suggest this may be due to a multitude of factors, including the increased pressures young women face these days from body shaming, discrimination in the work place, impact of porn, societal expectations of beauty, the economic situation and the insidious impact of social media, not to mention increased body dysmorphia and issues connected to sexuality.

    Thus, any allegation that contraception, which by itself protects women from unwanted pregnancy and the impacts of such an occurrence (which can include depression), is somehow a ’cause’ of depression, must be viewed with great scepticism.

    Take-home message: contraception does not cause depression, but perhaps careful prescribing in women more likely to suffer depression with individualised therapy is the optimal approach.
    Research score: 2/5