Rob McElhenney announced in a statement released this week that he has been diagnosed with "a host of neurodevelopmental disorders and learning disabilities".
The actor, 46 - who is best known for shows like It's Always Sunny in Philadelphia and Mythic Quest - shared the news with his followers on Twitter on Monday night.
He stated that he will go through "the full diagnosis" at a later date and revealed that whilst he wouldn't usually open up about it, he has a particular reason for having done so.
Rob - who is the co-owner of football club Wrexham AFC with his pal Ryan Reynolds - explained his motivation for discussing his diagnosis in a statement issued this week.
He wrote: "It's not something I would normally talk about publicly but I figured there are others who struggle with similar things and I wanted to remind you that you're not alone."
The actor and producer continued in the post shared on social media earlier this week: "You're not stupid. You're not 'bad'. It might feel that way sometimes. But it's not true".
Rob had began his statement by writing: "I was recently diagnosed with a host of neurodevelopmental disorders and learning disabilities! At 46! I go through the full diagnosis/prognosis on the @thesunnypodcast (which drops in 2 weeks)".
The tweet has amassed almost 30,000 likes on the platform and prompted hundreds of comments, with his followers expressing support and gratitude in response to the news.
One person wrote: "Great attitude. Thank you for spreading awareness on this". Another said: "Thank you for being so open and honest." A third said: "We're so proud of you".
"Inspiration. This is going to be such a help to many out there," wrote another person in response. Whilst someone else said in a tweet: "You're going to help a lot of people".
Another person said: "Your honesty will benefit many and the support you receive hopefully benefits you". Another follower wrote: "Thank you for sharing this with us".
Rob is set to further discuss his experience on the podcast that accompanies his show It's Always Sunny in Philadelphia, in which he plays the character Ronald 'Mac' McDonald.
The actor - who serves as a producer and also created the show, which premiered in 2005 - hosts a companion podcast alongside colleagues Glenn Howerton and Charlie Day.
His other credits include playing Ian Grimm in Mythic Quest and he appears alongside pal Ryan, 46, in the documentary series Welcome to Wrexham, which is about Wrexham AFC.
