The actress credited her roles in Thor and No Strings Attached with helping to restore her sanity and giving her a much needed dose of levity.
"[Thor] probably delayed the onset of a total breakdown from the efforts of doing Black Swan, which [was] going to hit at any moment," she told The Sun. "We got nice long breaks and I got to read in my trailer which was very comfortable and has a bed. I could eat whenever I wanted and train whenever I felt like it.
"Also I went on to do the Ivan Reitman comedy No Strings Attached as well. They didn't require a lot of research ahead of time. They didn't require any specific physical training. Both were very fun projects, surrounded by friends."
She added: "They were both the gentlest of any work experience I could have gone into after the extreme situation of doing Black Swan."
Portman recently revealed that she considers exercise to be the greatest form of stress relief.