Video report by ITV News Correspondent Sejal Karia
Cocaine Addicts Anonymous, unsurprisingly, do not let film crews into their meetings.
But this past Saturday night, one group made an exception for ITV News to highlight a route out of cocaine addiction.
The nine people gathered in this small room in east London came from different walks of life; the young and the old; current users and those now clean; some holding down jobs and others recently out of rehab.
But what they all had in common at one time was a cocaine dependency that dragged them to the very depths.
Over the course of an hour, they described, in explicit and moving detail, the impact this drug - seen by many as a harmless party extra - had on their lives.
"Cocaine became a necessity instead of an accessory," said Danny, 27.
He credits this group with saving his life; he has been clean ever since he joined nine months ago - a far cry from the "hopeless" situation he found himself in at the height of his addiction in his early 20s.
"It took me to some really dark places: to committing crime, to stealing off family and friends, to just being alone. It dictated how I lived and I couldn't see a way out."
Trevor, another former addict and designated "chair" of this session, spoke of how the fun times became few and far between before the drug took hold and left him "absolutely powerless".
Listening at the back of the room, we were struck by their honesty, sense of camaraderie and similar accounts of how quickly their party habit spiralled so rapidly into something far darker.
Their message is especially pertinent in Britain in 2019; over the three years to 2018, cocaine-related deaths in England and Wales doubled to reach their highest level ever: 637 fatalities.
The reason? Cocaine has never been more available, pure and affordable as it is at the moment. Crack cocaine use and the number of people injecting cocaine - both factors which increase the risk of death - have also increased.
As the potency and availability has increased, so too has the distress caused by the drug.
Back in the meeting, it was David's turn to speak.
"I keep relapsing; I'm really struggling," he said. "Is there any advice you can give me on how to get better please?"
Trevor, who earlier shared his path to recovery, offered his advice.
"Find a sponsor in this room - they need it to make themselves better too - and just surrender; Let down your ego, let down your guard, be honest and do everything your sponsor suggests and it will materialise."
Bowing his head, David quietly replied: "Thank you."
Chips to celebrate milestones of recovery - including David as he returns from a relapse "wanting a new way of life" - are handed out amid warm hugs and applause at the end of the meeting.
Speaking as we filtered out, Danny turned and said: "I would not be where I am today without it [CAA]. I was hopeless, my whole life was unmanageable.
"My life has completely changed. I have an amazing job, my family back, new friends who are really there when I need them and I am living in peace and doing everything without the use of cocaine. It can be done."
Names have been changed for the purpose of this report
Cocaine Addicts Anonymous meet four times a week in London; if you think you have a problem with cocaine, go to www.cocaineaddictsanonymous.com or call 020 7859 4039