She's currently receiving lots of praise for her starring role in Happy Valley as Catherine Cawood, but her road to success hasn't been easy.
Speaking to The Sun, the actress spoke about being diagnosed with depression, saying she first started experiencing symptoms of the illness when she was 17 years old and spent the following decade trying to find a way to deal with them.
Sarah said: 'Tranquillisers were the worst thing for it. I ended up in a terrible mess. My twenties were a write-off.'
Sarah plays Catherine Cawood in Happy Valley
The 51-year-old actress also explained why the condition is so 'cruel', as most people can hide it well from others.
'It's a cruel illness because you can't see it and you can hide it so well. At least, I can', she said.
'I'm a genius at hiding it. I think a lot of people are. Actors are bloody marvellous at hiding.'
Before playing Raquel Watts on Coronation Street, Sarah says depression made her life as a budding actress a lot more difficult.
'[I didn't know] what it feels like to wake up in the morning full of the joys of spring and wander through the day feeling capable of coping.
'In my early days depression did inhibit me because I was too debilitated and terrified to tell anyone why I couldn't get on a train from Manchester for auditions in London.'
The actress won a British Academy Television Award for her role in Last Tango in Halifax
Sarah got her big break in the soap in 1991 but while she was playing a cheerful barmaid in the show, away from the screens she was experiencing a difficult time.
She said she was able to deal with her illness during that period because of some time-off from work: 'Purely coincidentally, I had been written out of the Street for 10 weeks, so I was lucky. It was a time bomb waiting to go off.
'It was my mother who said, "Enough's enough". It must be dreadful to watch someone you love so debilitated, and she literally dragged me to the doctor. It gave me my life back.'
Leaving the show in 1996 coincided with her divorce from her first husband, Gary Hargreaves, and at the time she says she didn't want to even consider getting involved with someone else romantically.
Sarah played Raquel Watts from 1991 to 1996
Five years later that changed when she met top TV executive Peter Salmon, and the two got together in 2000. He and Sarah were engaged on 2001, and she said at the time: 'Look at me! It's very difficult to disguise how I feel. I just can't stop smiling.'
Although she's currently not taking medication for her mental health issues since 2011, Sarah says that that may change in the future. 'I know there will come a time when I'll have to, but for now it's OK.'