The coronavirus crisis poses the greatest threat to mental health since the second world war, with the impact to be felt for years after the virus has been brought under control, the country’s leading psychiatrist has said.

Dr Adrian James, the president of the Royal College of Psychiatrists, said a combination of the disease, its social consequences and the economic fallout were having a profound effect on mental health that would continue long after the epidemic is reined in.

As many as 10 million people, including 1.5 million children, are thought to need new or additional mental health support as a direct result of the crisis.

The prediction comes as the virus surges in the UK, and highlights the need for a plan that ensures those who develop mental illness or see existing conditions worsen have swift access to effective support in the years ahead.

“This is going to have a profound effect on mental health,” James said. “It is probably the biggest hit to mental health since the second world war. It doesn’t stop when the virus is under control and there are few people in hospital. You’ve got to fund the long-term consequences.”

Demand for mental health services dropped at the start of the pandemic as people stayed away from GP surgeries and hospitals, or thought treatment was unavailable. But the dip was followed by a surge in people seeking help that shows no sign of abating.

Data from NHS Digital reveals that the number of people in contact with mental health services has never been higher, and some hospital trusts report that their mental health wards are at capacity. “The whole system is clearly under pressure,” James said.

Modelling by the Centre for Mental Health forecasts that as many as 10 million people will need new or additional mental health support as a direct result of the coronavirus epidemic. About 1.3 million people who have not had mental health problems before are expected to need treatment for moderate to severe anxiety, and 1.8 million treatment for moderate to severe depression, it found.

The overall figure includes 1.5 million children at risk of anxiety and depression brought about or aggravated by social isolation, quarantine or the hospitalisation or death of family members. The numbers may rise as the full impact becomes clear on Black, Asian and minority ethnic communities, care homes and people with disabilities.

The threat to mental health has been used as an argument against lockdowns, but James said the mental health grounds for controlling the virus should not be ignored. Beyond the fear of becoming infected or having vulnerable loves ones fall ill, suffering severe disease can trigger mental health problems. About a fifth of people who received mechanical ventilation during the spring developed post-traumatic stress disorder.

Others are dealing with complex grief reactions after losing loved ones to the virus, often without being able to say goodbye in person. The potential for mental health problems emerging in people with “long Covid” is also a very real worry, James said, adding that uncertainties over employment, housing and the broader economic hardship ahead will only add to the burden.

To cope with the coming wave of demand for help, mental health services will have to be beefed up and made more accessible, James said. Young black men, for example, are often reluctant to seek early mental health care, a problem that needs to be solved through closer work with local communities.

Even once vaccines have been rolled out and the risk from coronavirus has receded, many people are likely to need help to restore their social support networks and get back into some kind of normal life, James believes.

“It’s very easy to think that when it’s safe to do so, we’ll all be out and about again straight away, but I think it’s going to take a while to get people used to that. The people most likely to suffer are older adults who have got used to self-isolating,” he said.

“We’ll need to support the voluntary sector, the charities, that help them get out of the house to socialise and engage in meaningful activities. We know that when you get older, if you lose your connections for a bit, you can give up on them.”