A former drug addict and dealer, Mark Dempster sold The Big Issue in the 1990s before he trained as a counsellor and launched his successful Harley Street practice.
He has also co-hosted a radio show with Russell Brand.
“I have led two lives – one before recovery from addiction and one after,” he says.
“The experience and support The Big Issue gave me during my early addiction recovery helped me regain control and become a successful therapist and addiction expert.”
