Mental health charities say they are concerned people may not be seeking help, despite suffering increased stress and anxiety during the coronavirus crisis.
Last April, NHS statistics show that 1,055 people were referred to psychological therapies for depression and anxiety in the NHS Wigan Borough Clinical Commissioning Group area.
But the latest figures show that this April, the number had fallen to just 390 – a drop of 63%.
There was also a drop in the number of patients who began therapy during the month – 425 compared to 885, a fall of 52%.
Across England, referrals were down by 57%, falling from 133,191 to 57,814.
The number of patients starting treatment fell from 95,070 to 62,375, a decrease of 34%.
Danielle Hamm, associate director for campaigns and policy at charity Rethink Mental Illness said the figures reflected the “significant disruption” to mental health services during the initial pandemic response.
Research carried out by the charity in April found 79% of people with pre-existing mental illnesses said their mental health had deteriorated because of the pandemic, while 42% said this was the case because they were getting less support.
Ms Hamm said: “We’re very concerned to see the number of referrals dropping so rapidly at a time when a significant number of people reported a deterioration in their mental health, combined with an increase in waiting times for those who have sought help.”
The NHS’s official measure of waiting times shows little change during April, as it only looks at the waits those who finished their treatment during the month faced when they were first referred.
But for those patients across England who were waiting for treatment at the end of the month, analysis shows 18% had been on the waiting list for more than 18 weeks.
That is a huge increase on the 5% who had been waiting that long in April last year.
The national standard is that no more than 5% of patients should wait more than 18 weeks.
Dr David Crepaz-Keay, from the Mental Health Foundation charity, said the figures were “troubling”, but that the health service is only one source of support for mental health.
He said: “There are many other ways the Government can support the mental health of the millions who have been especially hard-hit by the pandemic.
“This includes action to increase people’s financial and physical security, so they don’t have to fear running out of food or fuel or being evicted, as well as wider changes such as more health visitors to support new parents, and mental health support for people who work in the NHS.”
An NHS spokesman said the pandemic had turned lives upside down, but that therapy has always been available for those who need it.
He added: “Local services continue to adapt to maximise the mental health support available, including online and telephone support, and anybody who thinks they would benefit from psychological treatment can refer themselves directly.
“The NHS is here for you, please help us help you.”