Crichton's father confirmed on Thursday that the 27-year-old NSW State of Origin second-rower was receiving treatment for the condition and was being fully supported.
In a statement provided to Nine News, he also requested privacy for his son.
"Angus is under appropriate professional support and treatment for medically diagnosed bipolar disorder which he has been dealing with for some time," Charlie Crichton said.
"He is fully supported by his family, his management and the Sydney Roosters club as he works towards recovery.
"While no timeline has been set for his return to rugby league, we will continue to trust his medical team and know those within the rugby league community will respect his right to privacy."
Roosters captain James Tedesco this week said he had been in contact with his club, state and Australian Test teammate Crichton to offer support.
"It's important to. We've just been supporting him. He is going through some things at the moment." Tedesco said.
"We can't really go into detail, but we're all supporting him and hopefully he can be back training.
"He is an important part of our team. He was one of the best backrowers in the game last year so we miss him and want him out there playing with us."
Meanwhile Roosters centre Joey Manu remains in a race to be fit to face the Dolphins in the club's season opener on March 5.
Manu suffered a facial fracture earlier this month after he was hit by an errant elbow in training.
Jared Waerea-Hargreaves (back) and Luke Keary (jaw) are both expected to be available for the match.
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