Batsman Trott, 32, left England's Ashes tour as he bids to recover from a stress-related condition.
McIlroy has endured a tough year in golf and sympathises with Trott.
"As sport becomes so big it's becoming more common that these sorts of stress-related illnesses are happening," McIlroy, 24, said.
"It's sad to see something like that happen and it just shows what a mental toll sport can take on you sometimes.
"Hopefully he gets home and spends some time with his family and recovers and can come back."
The Northern Irishman's struggles on the course saw him slip from top of the world rankings to sixth following a winless run in 2013.
McIlroy's best finish this season was a runner-up spot at the Texas Open in early April, but with the exception of top-10 finish in the season's final major, the US PGA Championship, he admits it has been tough going.
"It's been a long year, I guess mentally more than physically," McIlroy said.
"Physically, golf doesn't take that much out of you but mentally it's quite draining, especially this year for me.
"It's not just the golf and being frustrated with my game, but having to answer the questions and having to come up with reasons why I'm not playing well and all that stuff."
McIlroy recently said "countless hours spent with lawyers this year" have been a "distraction" after a split from his management company.
But he wants to end a difficult year on a high with a positive showing at the Australian Open in Sydney which starts on Thursday.
The tournament is the first event in a new qualifying series for the 2014 Open Championship with three places for next year's major at Royal Liverpool available.
"I've said for the last couple of months I just wanted to try to finish this season strongly and get some momentum to go into 2014," McIlroy added.
"This would be the perfect place to get that first win of the year and give me a springboard into next season."