McPartlin underwent a stint in rehab last year to recover from an addiction to painkillers, he then split from his wife of 11-years Lisa Armstrong in January.
TV presenter Holden revealed that the star has managed to bounce back due to the support of his strong group of friends.
Speaking on Heart FM Holden revealed: “You know he's come back and it's absolutely fine.
“It feels like nothing happened and that's rare and it's because of his tenacity and his sense of humour about it all.
“That's the most important thing to keep when you're in this industry. It's hard sometimes to keep laughing [but] you'll be fine.”
Holden added how the other half of McPartlin’s dynamic duo, Declan Donnelly, had been “hugely supportive.”
“[Ant] has been in this industry since he was a kid so I think that he's got a strong backbone and I think he's got thick skin.
“I think he's got an amazing partner in Dec and I think the people that surround him have just been hugely supportive.”
According to The Sun, Holden and co-judge Alesha Dixon also offered support to make-up artist Armstrong, despite being close friends with McPartlin.
A source told the publication: “Lisa has been keeping herself to herself a fair amount while on Britain’s Got Talent this year for obvious reasons, as no one wants a big showdown.
“But Amanda and Alesha Dixon, despite being close friends with Ant, have been a real support for her.
“They’ve had a couple of late nights sat up chatting and helping her take her mind off things.”