SHARON Small is an actress with a huge career.

Since appearing alongside Michelle Collins in the 2000 drama, Sunburn, Small has been almost omnipresent in British TV drama.

The lady who grew up in Clydebank and then Kirkcaldy has played a range of English and Scots characters in the likes of Mistresses and the more recent Trust Me, alongside Jodie Whittaker.

Next year she’ll star in a new police drama, London Kills.

However, Small doesn’t see herself as a major success story.

“I’ve had a degree of luck in landing returning series,” she says of the likes of The Inspector Lynley Mysteries.

A degree? You’re never off the box, Sharon. “Ah, but the reality is there are six or seven names in the frame for the top jobs [on British television].

“I’m not in that category. I get to play the sidekick, or the supporting role.”

But you get these roles continually. You work harder than a Brexit civil servant. “I guess I do,” she concedes.

This work ethic, and constant striving for improvement, no doubt plays a part in Small landing some of the very best roles.

And Glasgow is set to see the actress take on one of the most demanding challenges she has faced.

The former National Theatre actress is starring in Still Alice.

This stage version of Lisa Genova’s book tells of Alice, a 50-year-old Harvard professor with early onset dementia (Julianne Moore picked up an Oscar in 2014 for the film role).

It’s a hugely demanding part. Small’s character has to be able to look inward and speak to herself. “I miss myself,” says Alice.

Small says it’s an immensely rewarding piece to do.

“When you get an immediate response from an audience it reminds you why you do this job.”

Does the subject matter frighten her? Michael Caine said recently he couldn’t play someone coping with dementia – it was too close to home.

“I felt I could do it,” says Small. “But I worked with Wendy Mitchell, our consultant [who is coping with dementia] who was honest with me. She helped me get the eyes, the walk right, and when I got the seal of approval from her I felt OK.

“But I have to add, this is a bespoke story; it’s not everyone’s story, although there is a real universality about it.”

The play has had a powerful impact upon audiences.

“One man who came to the show, a dementia sufferer, said he loved it. But then he smiled as he said he wouldn’t remember it the next day.”

The play has really brought home the impact of the illness.

“It’s scary,” says the actress. “We’re living longer. The plaques and tangles begin to cover your brain and affect people in different ways. Some get angry. Wendy however says she’s forgotten how to be angry.”

Sharon Small lives in London with her photgrapher partner Daniel and their two sons Zac and Leo.

Small grew up the oldest of five kids in a single parent family, in which life was challenging.

She reflects on the changing concept of childhood.

“They’re not daring themselves to do stuff. So much of our lives was about getting out to play. You’d go out, come back when you were hungry, for a piece. You had a bath once a week, all sharing the same bath.”

She laughs: “Dirty water. That’s what I remember. Now, kids’ lives are all organised play dates.”

Her laugh becomes louder and mocking. “And kids have showers!”

Sharon Small laughs a lot. Life is good. She has picked up great notices for her performance as Alice.

But chat reveals a woman who, despite a great career, doesn’t quite see it that way.

“Yes, life is good but there’s a sense I’ll never be Juliet,” she says, with a wry smile. “And I haven’t done the indie film that lifts you up into the stratosphere.

“It’s the very beautiful women who get that chance. I was never that sort of person. I’m too . . . curvy.”

But isn’t that better in the long run? “Yes, well, maybe. But if you’re Oscar-nominated you tend to stay in the frame for good work.” Has she done the casting rounds in LA?

“I did it once, still full of breast milk at the time,” she says with a little sigh, “and I didn’t really know what I was doing back then. But I’d love an American TV series.”

She adds, laughing; “Do you think I’m too moaney?” Yes. “Just wait ‘till you see me and I’m not working. You’ll be sorry you said that.”

Still Alice, the Theatre Royal, November 13-17.