For Jon, “being diagnosed with depression has affected every tiny atom of my life. I have lived through great highs and huge lows — lows where I have even tried to end my life.”

In Andrew’s case, “becoming disabled, an acrimonious divorce, work and financial stress was enough. However, losing contact with my three daughters was the final straw. All that had been keeping me going evaporated and I suffered a huge breakdown.”

Jacs has “lost a number of jobs over the years — I was even asked not to come back to my own business. At my lowest, I gave up on the idea of working again.”

Michael’s sister Samantha has “always struggled with her mental health. But when our mother died, it sent her into a downward spiral. As her carer, I worry every day about who will take care of her when I’m gone.”

Based on letters they had written, the stories of Jon, Andrew, Jacs and Michael were among those featured in an affecting appeal video at the London dinner of mental health charity Jami, which supports 1,300 people annually.

Two 12-year-old JCoSS pupils, Matthew and Alfie were also shown in the video, the former confessing: “Sometimes it’s hard to talk about my feelings because I don’t think my teachers and family really understand.”

The film subjects spoke of how Jami was helping them to get their lives back on track. For example, Jon — who at one point was “desperate for help, living in the back of a borrowed car, only eating once a day” — had, with Jami’s assistance, got off the streets, rediscovered his creativity and was seeking employment for the first time in more than two years.

“Maybe I’m just getting there. I’m alive today because of Jami.”

Speaking to the JC at the dinner, held at One Marylebone and attended by more than 300 supporters, Jacs (Jacquelyn Guderley) revealed that because of mental health issues, she had to take considerable periods off work “almost every year since 2012”.

The 31-year-old North Londoner, a high academic achiever working in the field of gender equality and social enterprise, recalled becoming “very anxious” after a breakdown. I thought I was dying. I cut myself off from everyone.”

Recommended to get in touch with Jami earlier this year, she was “apprehensive. I wasn’t socialising and I don’t like sharing my story. But they accepted me as I was. They are like a family. They made me feel I was cared for.”

Jami clients “all get one another”, she added. “We understand how hard mental health can be.”

Ms Guderley has been volunteering at Jami’s Borehamwood warehouse, involved in upcycling work. She has recently held down short-term jobs and said that with Jami’s support, “it’s got better and better”.

Michael (Fierstone) is feeling more confident about the future for himself and his sister since contacting Jami two years ago.

Mr Fierstone, 57, is based in Stanmore; Samantha, 51, lives in their late mother’s flat in Cockfosters and has not worked in years. “If you meet her, you would say there’s something not quite right but you would not be able to put your finger on what,” Mr Fierstone explained. “She can just about get by but needs help in running the home.”

His sister attends Jami’s Edgware centre and is supported by a social worker. “She has made friends, although she finds interaction very difficult,” he said.

“I can’t tell you how much of a difference it’s made. I also have the confidence of knowing I have people who will support me. I was desperate.”

The dinner crowd included two tables from Young Jami, whose chair, Gabi Mendelsohn, said mental health was “a major issue for our generation”. The guest speaker was entrepreneur and mental health campaigner Lord Dennis Stevenson, who during an informal and entertaining address, said he was “impressed out of sight with Jami”.

He could not think of a mental health charity operating on a similar scale in the non-statutory world. He added that from personal experience, “people in the depths of mental ill health who are loved don’t always feel it”.

Doug Krikler, Jami’s chair, said its challenge, “and our challenge as a community, is to focus both on early intervention and building resilience across all generations”.

Trustee Debbie Fox said the charity needed to raise £2 million annually and that demand for its services was increasing. More than £350,000 was raised on the night.