The number of adults experiencing depression has almost doubled during the coronavirus pandemic, new figures suggest.

Data from the Office for National Statistics (ONS) showed that nearly one in 10 (9.7%) British adults suffered some sort of depression between July 2019 and March 2020.

But when the same group was assessed again in June, the figure had risen to 19.2% – nearly one in five.

The majority (84%) of people experiencing some sort of depression cited stress and anxiety affecting their wellbeing, and 42% said their relationships had been affected.

The ONS research examined data from the same 3,500 British adults both before and during the pandemic.

Statisticians found those most likely to say they had been affected by depression in June were younger adults (aged 16 to 39), women, those “unable to afford an unexpected expense”, and disabled people.

Depressive symptoms include low mood and loss of interest and enjoyment in ordinary things.

Researchers also examined the levels of depression – which are classed as mild, moderate or severe depression.

One in eight adults (12.9%) developed moderate to severe depressive symptoms during the pandemic, while 6.2% already were already experiencing symptoms at this level.

Of those experiencing moderate to severe depressive symptoms during the pandemic, 62% said they felt lonely “often or always”, compared with 15% of those with no or mild depressive symptoms.

Just 3.5% saw an improvement during the same timeframe.

Tim Vizard, from the ONS, said: “Today’s research provides an insight into the mental health of adults during the coronavirus pandemic.

“Revisiting this same group of adults before and during the pandemic provides a unique insight into how their symptoms of depression have changed over time.

“Nearly one in five adults were experiencing some form of depression during the pandemic, almost doubling from around one in 10 before.

“Adults who are young, female, unable to afford an unexpected expense or disabled were the most likely to experience some form of depression during the pandemic.”

Commenting on the figures, Dr Billy Boland, chairman of the General Adult Faculty at the Royal College of Psychiatrists, said: “The doubling in the numbers of people experiencing depressive symptoms is another warning of the looming mental health crisis and the tsunami of referrals we are expecting over the coming months.

“Isolation, bereavement and financial insecurity are some of the reasons why the nation’s mental health has deteriorated since the start of the pandemic.

“The Government must speed up the investment to mental health services if we are to treat the growing numbers of people living with depression and other mental illnesses.”

Mark Winstanley, chief executive of the charity Rethink Mental Illness, said: “These statistics underline the mental health impact on the population at large, and also highlight the groups in society who more be more vulnerable to developing mental health problems, such as young adults, disabled people and those facing financial instability.

“Mental health problems can affect every aspect of a person’s life.

“It’s crucial that people seek help to manage depressive symptoms and are able to access services when they need them to prevent further deterioration in their health.

“We anticipate a significant increase in demand for services and support due to the pandemic, but it’s crucial to recognise that the responsibility for mental health goes beyond the NHS and demands a cross-government approach.

“Support with employment, housing and financial problems, for example, must all be prioritised now the country is in recession, and recognised for their role in supporting people’s mental health during a time of great uncertainty and strain.”

Sophie Corlett, director of external relations at Mind, said: “It’s worrying to see an increase in the number of people experiencing depression. We cannot underestimate the impact that the pandemic has had on the nation’s mental health – whether that’s bereavement, the devastating loss of life, the impact of lockdown, or the recession we are now in.

“It’s crucial that mental health and wellbeing are put at the centre of the UK Government’s ongoing recovery plans, so that we can rebuild as a kinder and fairer society for everyone.”

Sean Duggan, chief executive of the Mental Health Network, part of the NHS Confederation, said there are concerns that current funds will not be enough to meet increased demand for services.

He continued: “Meanwhile, Covid-19’s impact on the wider determinants of mental health such as housing, employment, debt and personal relationships has been significant.

“If social issues become more deeply rooted for a large section of the population, there is a risk that low level mental health needs will become more serious and require more specialist care.”

Claire Murdoch, national mental health director for the NHS in England, said: “The pandemic has turned lives upside down and for some people it will have put greater strain on their mental health, and while some people will have had understandable concerns about seeking help during lockdown, NHS services have been available for those who need them.

“The NHS will continue to maximise support on offer, including through online and telephone advice and the establishment of 24/7 crisis services, so I would urge anyone concerned about their mental health to come forward for help – the NHS is here for you.”

– The Every Mind Matters portal has information on coronavirus and wellbeing https://www.nhs.uk/oneyou/every-mind-matters/, and the charity Samaritans has a freephone number – 116 123