Andrea Leadsom is MP for South Northamptonshire.

Last week we marked Mental Health Awareness Week. It offered the chance to shine a light on the importance of good lifelong emotional health and why the building blocks for its success lie in the first 1001 days of life – the period from conception to age two.

The first 1001 days shape the health, wellbeing and even the life chances of every human being. Countless neuroscience studies have shown that the first two years are the most important phase of brain development, with volume doubling in size. In just the first three months of life, the brain grows by 64 per cent, becoming more than half the size of the average adult brain.

Healthy brains develop naturally when babies have a loving, secure relationship with their principal care-givers and these relationships are the very foundation of our developing emotions. They help to cement our future personality traits and impact on our social, economic and physical outcomes.

Perinatal mental illness is, however, widespread across all parts of our society. I’ve been open about my own struggle with postnatal depression, and I know how helpless and hopeless it can make you feel.

The impact on human happiness, relationships and potential is reason enough to address it: but there is also a huge economic cost. It is estimated that every year, the long-term cost of failing to address the mental health issues of new mothers, and the impact this has on the outcomes for their babies, is £1.2 billion to the NHS and social services, and £8.1 billion to society.

The NHS Long Term Plan unveiled new perinatal mental health support for mothers and their partners, and extended the length of time that support can be accessed to two years from their child’s birth. This should radically help to improve the support available.

On top of that, the Government has invested £365 million to ensure that by 2020/21, up to 30,000 more women can access high-quality mental health care in the community or in specialist Mother and Baby Units.

It’s good that there’s been a shift in attention towards this issue. But there is so much more to be done to ensure that the parent/baby relationship is at the heart of all perinatal mental health support.

At present, the baby is almost always the ‘third party’ and the last to be considered, despite being profoundly susceptible to the emotions of their parents – and often with longer-lasting effects. Parent-infant specialist support is needed in those cases; and at the moment, there are too few skilled specialists in this field.

I was proud to chair an Inter-Ministerial Group on the early years, between 2018 and 2019. This cross-Whitehall group worked collectively on how we can develop good perinatal mental health services, as well as a whole raft of support measures that would ensure every baby gets the best start in life.

As part of our work, we visited support services across the UK and consulted with a wide range of parents with hugely differing needs. We looked at best practice and at the ‘postcode lottery’ to see what services were on offer to families, and what was missing. We took advice from a specialist panel of practitioners, as well as from academics in the early years arena. The Ministers who took part in the IMG gave their recommendations to the government in July 2019, shortly before Theresa May resigned.

My own return to the backbenches means I can now focus on taking forward this early years work, and I am delighted that our new Prime Minister has promised to support me. The wheels are in motion, and I am looking forward to making a real, positive difference to this critical period of life.

I am certain that by providing world-class support in the vital early years, we can change our society for the better. Supporting the development of secure attachment between new babies and their caregivers will lead to happier, more capable and healthier children, and ultimately, a stronger society.

Infant mental health is about more than babies. It’s about improving our whole lives, and striving for better outcomes that have a profound effect from cradle to grave.