The Newcastle 36-year-old, who has Asperger’s spectrum disorder, will tackle his first marathon alongside more than 100 competitors in the Newcastle Running Festival.

It will cap a genuinely life-changing year for Mr Brown, who attributes a stint working with the Samaritans to his complete transformation.

Mr Brown said he had been in and out of institutions most of his life and had struggled with gambling and substance abuse since he left home in Cooma aged 16.

He gave up drugs for good in March last year.

‘‘A year ago I was in a bad frame of mind, addicted to crystal meth and diagnosed as a paranoid schizophrenic [with] paranoid psychosis,’’ Mr Brown explained.

‘‘Since taking up running I no longer have those mental health problems.’’

Mr Brown’s transformation came through the Recovery Point Project, a NSW Health-funded Samaritans Foundation program which is designed to help people re-integrate back into the community after rehabilitation or prison.

Mr Brown will run this weekend to raise money for Ronald McDonald House. But he said it was the coastal scenery, the challenge and the social interaction that drew him to running and kept him motivated.

‘‘My life was hell,’’ Mr Brown said.

‘‘Running has made such a big difference in my life.’’