Experts have confirmed what almost every woman who is taking, or has taken, the oral contraceptive pill already knew: those little buggers can affect your mood.
In an article for the June edition of the independent, peer-reviewed journal Australian Prescriber, psychiatry experts Dr Eveline Mu and Professor Jayashri Kulkarni from Melbourne's Monash Alfred Psychiatry Research Centre confirmed that certain brands of oral contraception - largely referred to as 'the pill' - may suit some people better than others.
Evidence suggests that changes in mood, including the onset of or worsened depression and anxiety, may be related to the hormones in the pill - the most popular and widely used method of birth control.
However, lower-strength pills are less likely to cause disruptions, the authors noted. Most pills today have 35 micrograms or less of oestrogen, an amount that's generally called "low dose". Common combined oral contraceptive pills with lower doses of hormones - oestrogen and a progestogen - include Levlen ED and Yasmin. In recent years there's also been a trend toward even lower levels of hormones: "ultra-low-dose" pills have 20 micrograms of oestrogen or less. Some examples available in New Zealand include Yaz, Microgynon 20 and Femme-Tab ED.
The team said both doctors and patients should be aware of these possibilities and explore different types of contraceptives, particularly if patients develop new or worsened symptoms of depression after taking the pill.
However, they stressed that many women taking hormonal contraceptives do not experience mental health issues.
"Finding contraception that suits you depends on a number of things. Your age, what you've tried before, your general health, and also your mental health," Professor Kulkarni said.
"One of the most common reasons for women stopping the pill is changes in mood, such as feeling depressed."
She noted that some hormones are known to affect mood more than others, which is why it's important that people are being prescribed the right brand of pill.
"Pills include ingredients called progestogens, or a mix of progestogens and oestrogens. Pills using lower strengths of these seem to be less likely to cause mood changes," she explained.
"If you have depression or have had it in the past, certain pills might suit you better than others. Everyone is different. But if you feel your pill is affecting your mood, it's really important to talk to your doctor. Let them know if you have started or changed your pill recently.
"The good news is that there are many choices. Talk with your doctor to find a method of contraception that suits you."
The authors noted many of the older oral contraceptive pills which contain ethinylestradiol - an oestrogen medication - are linked to severe mood problems. However, newer oral contraceptives containing physiological forms of oestrogen may be better tolerated, with a purported weaker link to changes in mood.
A large study also showed a positive association between the use of an IUD containing levonorgestrel - a synthetic progestogen similar to progesterone - and depression, anxiety and sleep problems in women who did not have these conditions before using the IUD. The study suggests that the lower-dose IUD may be more tolerable in terms of mood, as it only releases small amounts of levonorgestrel. However, there is no data yet on the relationship between its use and the development or exacerbation of depression.
As part of their report, Dr Mu and Dr Kulkarni have urgently called for primary healthcare practitioners to be provided with general community education and improved information and resources regarding the relationship between oral contraceptive pills and depression.
"Progestogen-only contraception seems to create a greater propensity for depressive disorders in vulnerable women. Further research is required to determine why some women experience hormonal-contraceptive-precipitated depression and anxiety, while many women taking hormone contraceptives do not experience mental health issues," the experts said.
"It is critical for clinicians to consider the history given by many women of a clear temporal relationship between starting or using a hormone contraceptive and the development of new or worsened depression. In such cases, exploring different types of contraceptives, including barrier methods, is an important patient-validating and therapeutic discussion."
