Jason first found fame in MTV reality show Laguna Beach: The Real OC, before landing a role in spin-off The Hills, but soon his life began to spiral out of control.
In a recent blog post, Jason revealed that he would "snort as much coke and drink as much alcohol as he could" during his troubled days. He eventually entered TV show Celebrity Rehab with Dr Drew in 2010 and began to clean up his life.
Yesterday (27 July), Jason took to Instagram and told his followers that it has now been four years since he last dabbled with drink and drugs. Alongside his post, he shared a picture of himself during his darkest time and one of him now.
Jason said: "I meant to post this on July 23rd when I celebrated 4 years of sobriety!! Miracles do happen ;) I appreciate all the people who have supported and help shape me into the man I am today."
Now 27, Jason was just a teenager when he stepped in front of the camera for the first time. He was most known for his relationship with leading lady Lauren Conrad however, behind the scenes, he was struggling with substance misuse and their relationship crumbled.
At his worst, Jason was arrested six times for alcohol related offences.
Since taking part in a 21-day detox programme for Dr Drew's show, Jason's life has settled down and he is now happily married to wife Ashley Slack, following a Californian ranch wedding last October.
Good work, Jason!
Laguna Beach: Where are they now