The development of the contraceptive pill was considered such a ground breaking moment for women’s liberation. Perhaps this is why we never really questioned whether we should take synthetic hormones and what the cost would be to our physical and mental health.

Over the years the main reason women have given for stopping taking the contraceptive pill is low mood. A recent study has confirmed that there is a link between depression and the contraceptive pill. What’s more it is young women that are more likely to suffer and those with pre-existing low mood are likely to find their symptoms exacerbated. And in case you think that an implant, patch or hormonal coil might be better, the evidence suggests that depression could be more likely with these types of contraception.

There has been a great deal of discussion about the findings of the Danish study which looked at users of the combined and mini pill over a period of thirteen years. When looking at the data from this longitudinal study along with reports from women who have taken the birth control pill there seems to be little doubt that in some people the pill can make you depressed. However, no-one seems to explaining why this happens.

I suspect that one of the main reasons the birth control pill can make you depressed is because of the way it depletes the key nutrients zinc and B6. This could explain why teenagers are more susceptible to depression on the pill. Teens have an increased need for zinc and lower levels of it are linked with low mood, clinical depression and other mental health issues. B6 is also vital for the formation of neurotransmitters, including serotonin which helps us to feel balanced and happy.

Hormones also have the ability to affect neurotransmitter balance, too little oestrogen, perhaps from the progestogen only pill – can cause a dip in serotonin levels. Too little is known about the effect of synthetic hormones on our physical and mental health. We do know that the combined pill can increase thyroid and Sex Hormone Binding Globulin (SHBG) which in turn actually reduces our levels of testosterone and thyroid hormone in circulation. Sub-optimal thyroid function can result from this, which can leave us with low mood and other health issues too.

Common signs of low thyroid function include loss of libido, tiredness, weight gain or difficulty losing weight and low mood. Sometimes there can be hair loss. There are a number of factors that can lower thyroid function in an individual and taking the contraceptive pill is one of them.

Women taking the pill are more likely to have insulin resistance or higher markers of C – reactive protein, a marker of inflammation. C-reactive protein is often raised in people with chronic inflammatory conditions such as rheumatoid arthritis and lupus, but it has now been identified as present in people suffering with depression. Inflammation is considered to be a major driver in depressive illness and may explain why women taking the pill are more prone to this illness.