The added disability from which our health system suffers is the isolation of mental health from the rest of the health services.” So said Nye Bevan, the founder of the NHS, in 1946, two years before the creation of what is now the world’s largest publicly funded health service. It’s still true. Mental health services, the poor relation of the NHS, are often delivered on remote sites in dilapidated buildings. My clinic room is a windowless cupboard.

A safe space: NHS unit on frontline of child mental health crisis Read more

Praise has rightly been lavished on the NHS as it marks its 70th birthday. It is impossible to overstate the significance of its spectacular achievements. There should be celebration, there should be cake – and there was. It came in the form of Theresa May’s promise of a £20bn-a-year cash boost by 2023. But our country’s mental health services badly need a bigger slice. May admitted as much as she announced the funding, noting that: “As the NHS has grown, mental health was not a service that was prioritised.” To redress that, the “cradle to grave” NHS, for so long a source of national pride, must be rethought.

The service has retained its founding principles, including “comprehensiveness within available resources”. But the needs of people with mental illness have not been truly considered part of that “comprehensive” healthcare.

There has been some progress over the decades. When I started work on NHS mental health wards 30 years ago, some patients were still being incarcerated for life in asylums as a result of illnesses they had long recovered from. This would, thankfully, be unthinkable now.

But when it comes to the resourcing and scope of care, there is still an unacceptable divergence in the way we treat physical and mental illness. There is no bigger indictment of this state of affairs than the significantly stunted lives of people with serious mental illnesses, whose life expectancy is reduced by 10 to 20 years. That’s far too many missed birthdays.

So what would a truly comprehensive “cradle to grave” NHS service that took mental and physical health fully into account look like?

Crucially, it would begin before the cradle. A good start in life is inextricably linked with a mother’s physical and mental health. Until recently, there was minimal support for the many mothers who experience mental illness during pregnancy and immediately afterwards (the perinatal period). These untreated illnesses can have a severe impact on their children’s development.

A signal achievement of the NHS in recent years is that 7,000 women have accessed specialist perinatal mental health support, their children benefiting in turn. This is world-class care, but we must not forget what a low base we are working from. A future NHS should provide universal perinatal mental health support. Antenatal classes including mental health advice, with support for fathers, should also be available.

When it comes to the mental health of young people, it certainly doesn’t take a doctor to tell you that there is “something going on”. We just don’t know the scale of mental illness among children, or the extent of unmet need. It has been 14 years since any proper review of the subject has been carried out. That’s 14 years in which the digital revolution has transformed the lives of those growing up today.

Simon Stevens, the chief executive of NHS England, says that long-awaited figures on children and young people’s mental health, due this year, are “bound to show that the level of undiagnosed mental health problems and distress among young people is much higher than has officially previously been recorded”.

That the problem is recognised will be a start. In the long term, expectations and ambitions need to be raised. We need to aim to treat the majority of young people who have a mental illness, not the minority.

As for the mental health problems experienced by adults, how can such a gulf, of up to two decades, emerge between the life expectancies of people with and without some types of serious mental illness? A large part of the answer lies with the care received, or not received.

Recent focus has been on quite specific areas, rather than on “general” services for people with long-term serious mental illness and psychosis. Services that support these people are being cut back, and early intervention services are patchy. The whole country knows about it when A&E departments see 90% of patients within four hours, rather than 95%. We have no idea how long people are waiting for mental health crisis treatment.

At the same time, increasing numbers of people are being detained under the Mental Health Act. “Those with the most severe forms of mental illness have the greatest needs, and continue to be the most neglected and discriminated against,” states the interim report of a review of the act. The neglect cannot go on.

Finally, what about older people – those who, like the NHS, are now looking beyond their 70th birthdays? Whereas in 1948, women could expect to live to the age of 70 and men to 66, today those figures are 83 and 79 respectively.

Our ageing population is no secret. Again, no medical degree is needed to guess that this poses a challenge to the whole NHS. But old-age mental health has not been prioritised in recent years. The consequence is a lack of services and staff. I work with older people, and our disjointed health and social care system is far from meeting their needs. No one wants to have to repeat their story endlessly or to different health professionals, especially not older people with complicated mental illnesses that often intertwine with physical conditions. No one wants to attend lots of different hospital appointments in different places addressing isolated problems, especially not an 80-year-old with many, interrelated difficulties.

The progress – particularly recent bounds forward – that has been made in public attitudes towards mental illness and available services throughout the 70 years of the NHS is invaluable. But we desperately need to keep up the momentum, to encourage a greater number of medical students to choose psychiatry, or the opportunity to provide comprehensive care and change the lives of the millions in this country living with mental illness will be lost. The NHS and its patients will continue to suffer.

By the time the NHS reaches 80, I want “cradle to grave” to really mean something different, more comprehensive and better able to meet 21st-century challenges. Another slice of cake, please.

• Wendy Burn is president of the Royal College of Psychiatrists