He said he hoped sharing his experience would help others struggling with their mental health.
Mr Greenhouse chose to run a marathon in each of England’s 48 counties, with four additional marathons in Cardiff, Istanbul, Dubai and at Egypt’s Pyramids of Giza.
He had to complete four of the runs in just nine days after taking six weeks off to recover from an injury.
He said the challenge had made him realise how mentally strong he was to get through his struggles with depression.
“Although I’m physically running marathons now, I was mentally running marathons for a year straight four years ago,” he said.
“Most of these marathons have been easier than getting into uni, when I used to shake at the thought of social interaction and getting up, brushing my teeth.”