The psychology of being a novelist

She's not especially enamoured with the prospect of being labelled as an author who started writing comparatively late in life. After all, it's the quality of her work that matters, not how old she was when she wrote it. But her two novels to date do benefit from a maturity of outlook, a depth of insight and a sureness of purpose that the vast majority of bright young things can only hope to imitate.

The Death Of Lomond Friel, which won the Saltire Society's First Book Award for 2010, concerned a radio presenter whose father hatches plans to commit suicide after he suffers a stroke. Superficially, it shares some similarities with her new novel, Snake Road. Its protagonist is Aggie, a married woman in her thirties, who also has to cope with the loss of faculties and impending death of a dearly loved older family member.

Her grandmother, Peggy, is suffering from Alzheimer's and Aggie is determined to preserve and understand what is left of the old lady's memories. Her gran has been making references to things which aren't part of the family folklore: a dead and buried daughter and a name, Eleanor.

Convinced that this is more than just flotsam from her grandmother's confused mind, Aggie sets out to establish whether Peggy really did have a secret child who she buried with her own hands. Aggie's curiosity brings her into conflict with her husband, who accuses her of obsessiveness and neglecting their marriage, and who may, Aggie suspects, have already begun an affair.

Peebles says that she wasn't consciously building on the themes of The Death Of Lomond Friel, but that family is central to her as a writer – "Relationships will always be to the fore. I don't think I'll ever write an issues-driven book" – and that Alzheimer's, for several reasons, was a natural subject for her to explore.

"It's a condition that has impacted on my life professionally, but more profoundly personally," she says. "When I finished the book and started to look back at it as a whole piece, I could see quite a lot of resonance in it from my own life that I had unconsciously drawn from – particularly in relation to some of the events surrounding Aggie and her backstory, really, because my paternal grandfather developed Alzheimer's back in the 1980s. Although I didn't see him that often, I was absolutely besotted with him. He was a hero in my life.

"He was eventually hospitalised in a monolithic place in Shotts, and I have very vivid memories of visiting there and being struck by the amount of good intention but poor execution in terms of his care. And also being struck as well by how poor they seemed to be at understanding the illness they were responding to, despite this fantastic edifice and the vast amount of resources that went into that aspect of healthcare."

With the exception of segments set in a support group, the words "Alzheimer's" or "dementia" don't appear in Snake Road, labels being anathema to Peebles, both as a psychologist and a novelist. But the condition continues to fascinate her. "Now I'm very interested in the sort of disinhibition that comes with Alzheimer's, the fact that you start peeling back all those years and years of socialisation that mould us into who we are in terms of how we conduct ourselves in society, all of that learning goes and you're kind of left with a core personality, if you like. At one time, one of my working titles was going to be The Persistence Of Self."

Another link between Peebles and her creation, Aggie, becomes apparent when it is revealed that the character, like the author, started university studying English literature before switching to psychology. For all her life-long love of books, Peebles found the clinical insight into human personality too tempting to pass up.

"I got interested in those concepts of personhood, what makes us who we are, how much of us is constituted by memory and therefore all the difficulties that arise when that starts to go," she explains.

Studying psychology put Peebles on her career path and, when she started to write fiction, left her with a "knowledge base" to draw on. Indeed, the psychological depth of Snake Road is one of its strongest elements. But her later experience in social work, dealing with families in difficult circumstances, proved just as valuable.

"The essential skills that I acquired in social work, I think, helped me as a writer in terms of not making judgements or assumptions but developing a way of observing which kind of puts aside your own values and helps you see something as it is. You're initially dealing with observations in a very direct way and only then getting to the interpretations."

As she has got older, Peebles has become increasingly interested in the effect of having lost both parents, a state she feels is rarely talked about – "because it tends to happen when you're older, if you're lucky" – although being orphaned at any age, of course, has a profound impact. One can see the parallels with Alzheimer's. Whether a parent dies or begins to fade away, a part of oneself disappears along with their memories, a reminder of our own fragility and impermanence.

It's not surprising to learn that what spurred her on to achieve her cherished ambition of writing a novel, even if it was never published, was the death of her mother. "It was the sense of mortality and time running out, and being that bit older, so being able to create the circumstances to find the time: ie leaving my job. Also, part of me needed something to say."

Giving up her salary, she took a year off to write her first, unpublished, novel. "I moved into the boxroom that houses the boiler and has a view of the river. And it was wonderful," she recalls. After her year off, she went back to work, lecturing in Dundee, assuming that, now she had a book under her belt, "the inclination would go – but it actually became much stronger".

She quit completely to write The Death Of Lomond Friel, although she still does some lecturing to pay the bills. "It wasn't that I was taking a risk leaving – I would have been taking a bigger risk if I'd stayed, in terms of doing what you want to do with your life."

Just before venturing back out into the sun, she alludes to Alzheimer's again, saying matter-of-factly that she expects it's lying in wait for her too. "The odds are on. My grandfather and one of my grandmothers had it. I'm not speaking scientifically, but in my observation there's a lot of carry-over between grandparents and grandchildren. Lots of things skip a generation, so it's my turn." She pauses, and adds: "But then I've always had a poor memory, so I have to remind myself it's always been that way."

Snake Road is published by Chatto & Windus at £14.99

Sue Peebles is at the Edinburgh International Book Festival on August 14