The 32-year-old British actor began treatment at a facility in Connecticut several weeks ago, according to reports.
In a statement, his representative said: “Kit has decided to utilise this break in his schedule as an opportunity to spend some time at a wellness retreat to work on some personal issues.”
Kit played Jon Snow in Game Of Thrones, which came to an end last week after eight hugely successful seasons.
A documentary about the show, The Last Watch, was released on Sunday and showed the star in tears when he learned about his character’s fate.
In a recent interview Kit spoke of “a huge heave of emotion” after filming the final scenes.
He told Variety: “You have these in-jokes, and these relationships that thrive for eight years.
“That’s a long time for those jokes to be going, and they never felt old or tired. In the last season, I was like, these are getting tired now.
“And I think they got tired because we could see the end coming.
“That’s a way of emotionally detaching from something: relationships very slightly starting to strain, just on the edges, just frayed.”
In another interview with Esquire, Kit discussed how he broke down while filming his final scenes in the fantasy series.
“The final day of shooting, I felt fine… I felt fine… I felt fine… Then I went to do my last shots and started hyperventilating a bit,” he said.
“Then they called, ‘Wrap!’ And I just fucking broke down. It was this onslaught of relief and grief about not being able to do this again.”
Earlier this month Kit’s co-star Maisie Williams discussed how she felt pressure to pretend “that everything is fine” whilst growing up in the public eye.
Useful websites and helplines:
- Mind, open Monday to Friday, 9am-6pm on 0300 123 3393
- Samaritans offers a listening service which is open 24 hours a day, on 116 123 (UK and ROI - this number is FREE to call and will not appear on your phone bill.)
- The Mix is a free support service for people under 25. Call 0808 808 4994 or email: email@example.com
- Rethink Mental Illness offers practical help through its advice line which can be reached on 0300 5000 927 (open Monday to Friday 10am-4pm). More info can be found on www.rethink.org.