'I started ketamine at 14 and needed nappies at 22' - the rise of young people going to rehab

Mark said his health had deteriorated to such an extent that "at the age of 25 I probably had the body of an 80-year-old".

"I was no longer functioning like a proper human being," he said.

As a keen footballer growing up in Liverpool, he now looks on jealously at others his age, walking without pain.

"It stopped me being a father to the little girl that I've got - I stopped being the big brother, the responsible son," he said.

Mark would regularly pass clots and experience pain during urination, but said the collapse of his nose from snorting drugs has had a huge impact.

"It completely destroys self-confidence - which leads to more drugs, because that just blanked out what I think of myself."

It's one of the reasons he has asked to remain anonymous.

"I started getting looks of disgust from my own family, which destroyed me. It was a very lonely time through my addiction," he said.

Mark's drug use started at 18, but by 21 he said he was using "copious amounts of cocaine and ketamine".

He initially sought help from his GP in Liverpool, but was too ashamed to admit he was using ketamine for fear of being dismissed or judged.

"It's a hard lesson learned," he said.

It's an issue reflected in Quelch's research. He found young people struggled with A&E and GP surgeries, as their symptoms weren't always linked with ketamine use, or the question wasn't always asked.

"That's not necessarily because people aren't asking the right question, but we don't actually know what works well at the moment," he said.

"There's very little provision for young people experiencing drug and alcohol-related harms, and that has almost left us starting right from the beginning."

Moore said things were improving, with greater availability of early intervention in the community, reducing the need for detox.

"We're seeing less people presenting to services with a new substance use of ketamine - so the education in schools, colleges and universities is actually working.

"But we are seeing an increase in people that have been using for a couple of years that we are going to continue to have to help and support."

With trends in drug use evolving, Moore said the challenge for both the third sector and the NHS was to adapt around the needs of clients, but that the involvement of those with lived experience had made a difference.

"I can see improvements now, but there have been some really difficult times where it felt like we were shouting in the dark."