People must not “undervalue their mental health” during the coronavirus outbreak, the NHS lead for mental health said, as she expressed fears that those struggling may not come forward.

The number of people seeking help has dropped during the crisis, said NHS England’s mental health director Claire Murdoch, but the NHS is ready to move “very, very fast” to respond to a predicted imminent surge in need.

There were 15,242 fewer referrals of children and young people for NHS community mental health services in England in March, compared with February, NHS England said – a 21% fall.

Some 57,531 children and young people were referred in March, compared with 72,773 in February.

During the month, 319,520 children and young people attended treatment sessions, down from 331,749 in February, but an increase from March 2019.

We want people, if they are in any doubt at all, if they are struggling with their sleep, with their appetite, with unwelcome thoughts, if they are feeling despair or desperation, we want them to come forward

While the mental health impacts of the crisis are reaching all parts of society, children and young people are the group the NHS is “watching most carefully at the minute”, Ms Murdoch said.

But she said the NHS is worried about people not coming forward because they feel “perhaps they don’t deserve to ask for help when the whole country is in the midst of a crisis”.

During her first interview on the pandemic, she told the PA news agency: “We want people, if they are in any doubt at all, if they are struggling with their sleep, with their appetite, with unwelcome thoughts, if they are feeling despair or desperation, we want them to come forward.

“We know that there has been a reduction in people coming forward for help during this period, and I’m told by experts that’s a common phenomenon during periods of extreme crisis, that people kind of lock down, put a stiff upper lip on it.

“And that might be appropriate for a very short while, while you’re working out a safe way to get help, but we, the NHS, have been here throughout, we don’t want people to think they shouldn’t bother the doctor, or don’t want to be a trouble.

“We definitely know there will be some groups of people who don’t like to bother the NHS when we are going through such a challenging and difficult time.

“I want to say really loudly and clearly to those people, please do come forward, please don’t undervalue your mental health, don’t suffer unnecessarily.

“If you’re worried about yourself, or a child or a friend, please come forward.”

Charities supporting people with eating disorders and obsessive compulsive disorder (OCD) are reporting “fairly considerable increases” in people calling their helplines, Ms Murdoch said.

There have also been a number of deaths the NHS is concerned about, but it is too early to say there has been a rise in suicides.

She said it is also too early to put a number on how many people will be affected and need mental health treatment.

If you’re worried about yourself, or a child or a friend, please come forward

The NHS is working with international experts on post-traumatic stress disorder (PTSD) and others who have knowledge of the aftermath of previous tragedies and disasters, to track what the impacts of Covid-19 will be, in addition to those around which they are already expanding services.

It is “significantly ramping up” and adapting its talking therapies, including for PTSD, and planning “very active” outreach programmes to target areas or populations most at risk.

This follows the roll-out of a screen-and-treat PTSD programme for those affected by the Grenfell Tower fire in June 2017, which cost 72 lives.

Ms Murdoch, chief executive of the Central and North West London NHS trust that led the response, said the aftermath of the west London tragedy had shown her “the power of community in keeping people safe”.

She added: “We will definitely be taking some of the extraordinary learning from Grenfell and feeding it into the national response.”

The NHS is also increasing its use of digital consultations, while a mental health inequalities taskforce will help services reach out locally.

The response will also be dependent on how wider society is affected, as mental health is “inextricably linked with the economy”.

But Ms Murdoch said not everything people are experiencing needs “to be medicalised”, and is calling on families, workplaces, schools and neighbours to provide support to one another.

Communities should keep a close eye out for people who may be vulnerable, and signpost them to professional help if they need it.