The Royal College of Psychiatrists says the coronavirus pandemic is the "biggest hit" to England's mental health in generations and has urged the Government to address growing referral lists across the country.
NHS Digital figures show around 49,905 people in the NHS Sheffield CCG area were referred for a mental health appointment in 2021 – up from 43,450 the year before.
Nationally, 4.3 million people were referred for mental health care last year, up from 3.7 million in 2020 and the highest number since records began.
The number of people in contact with mental health services across the country has also increased.
At the end of last year, 1.35 million people were working with mental health services, up from 1.26 million at the end of 2020.
Approximately 16,910 were using mental health services in Sheffield on December 31, up from 12,415 the year prior.
NHS England says the national rise in mental health referrals has resulted in a backlog and increase in demand for services.
In a recent report, it estimated 1.4 million people eligible for mental health care across England were yet to receive it, with a further 8 million deemed to benefit from accessing help if barriers preventing people from accessing care were reduced.
Dr Adrian James, President of the Royal College of Psychiatrists, said government silence on the issue "continues to be of grave concern" and called for a fully-funded plan to aid mental health services to deal with the backlog.
"The warning of the long tail of mental ill-health caused by the pandemic has not been heeded," said Dr James.
"Many thousands of people will be left waiting far too long for the treatment they need unless the Government wakes up to the crisis that is engulfing the country."
The Department for Health and Social Care said an extra £2.3 billion per year will be invested in mental health services by 2023-24, on top of £500million apportioned to tackle the pandemic's impact on mental health.
The number of children accessing mental health services has also increased, with more than 1 million under-18s across England in contact with health professionals for the first time at the end of 2021.
Roughly 3,020 of them were in Sheffield, up from around 2,810 at the end of 2020.
Mental health charity SANE warned the Government it is "sleepwalking" into a crisis due to the rising number of children requiring support nationally.
"The Government has promised a national conversation on a new mental health strategy later this year, but we need urgent action or our failures to act now may leave us with a lost generation," said Marjorie Wallace, chief executive of SANE.
A Department for Health and Social Care spokesperson said it will launch a "national conversation" about mental health before publishing a long-term Mental Health Plan later this year.