ita Simons meditated every day for two years to help herself "calm down".
The former "EastEnders" star suffers from insomnia due to her "overactive" brain and she has also suffered from anxiety for as long as she can remember, but she found it "life-changing" to meditate for 15 minutes a day.
She said: "I have traits of ADHD - I have overactive adrenal glands, which means I have to train a lot to get rid of excess energy.
"I'm confident, strong and not afraid of confrontation - you wouldn't want to mess with me, but I do have anxiety.
"I've been anxious for as long as I can remember. For two years I religiously meditated every day for 15 minutes, and it was life-changing.
"I used the Headspace app - it really helped calm me down."
While the 41-year-old star - who played Roxy Mitchell in the BBC One soap from 2007 to 2017 - can survive on four hours sleep, she sometimes cannot get any shut-eye at all and has to "stare at the wall for 12 hours" hoping she will drop off, which turns into an "all-nighter".
She added to Closer magazine: "It's been on and off since I was a kid. Some nights, I pull an all-nighter because my brain is overactive.
"I'll stay up worrying about the same thing and, by 4am, it's become the world's biggest problem.
"I tend to stare at the wall for 12 hours, which is horrible. I feel horrendous all day, but I have to work and I've got kids to look after, so I get on with it."
Rita recently admitted she suffers from numerous conditions, including OCD (obsessive-compulsive disorder) and depression, and said her insomnia is "like torture" at times.
She explained: "I suffer with a million "isms", including ADHD.
"I also have really bad insomnia. The worst is when I can't sleep at all and I'm up all night.
"Some nights I'm awake just staring at the wall. I don't even watch TV or listen to music. It is awful. It is like torture."