Philippa Perry lives in a tall old townhouse in a leafy square near London's King's Cross, with her husband Grayson, their daughter Flo, Grayson's teddy bear, Alan Measles, and a large and terrifying Maine Coon cat called Baddie. Like the rest of the house, the sitting room is filled with art: Grayson's glazed ceramic pots line the shelves, one commemorating the couple's wedding in 1992; propped against the sofa is a series of small canvases, on which Philippa has copied the dot paintings of Yayoi Kusama in felt-tip; and on the wall is a vast portrait of Grayson in a wedding dress. He's a Turner Prize-winning artist and Britain's best-known transvestite. She's a psychotherapist.
Obvious first question: is Grayson as intriguing a psychological case study as people might assume? "He's my husband!" Perry responds. "I've been with him since 1987. He's like one of my limbs! I can't see him like other people see him. He's my friend, my lover, my confidante. I'm so used to him."
But there was a time, wasn't there, when psychotherapists might have tried to "fix" cross-dressers? "People tried to fix homosexuality as well. But I hope we've moved on from that. Honouring an individual's subjective experience is basic psychotherapy."
Basic psychotherapy is the subject of Perry's new book, How to Stay Sane, part of a series of six small self-help paperbacks published by The School of Life, Alain de Botton's idea-sowing social enterprise. As someone who'd instinctively resist therapy and ridicule self-help, I found the book genuinely interesting, and potentially helpful.
Perry breaks her discipline down into four essential areas: "self-observation", "relating to others", "stress" and "personal narrative". After explaining the significance of each, she suggests useful exercises. Self-observation, for example, can be improved by keeping a diary, or even a daily breathing exercise.
For relationship aids, look no further than the "Daily Temperature Reading": a structured half-hour conversation between friends, lovers or family members, in which you offer and receive "appreciations", discuss your mood and your hopes, and provide each other with constructive criticism. "It's an amazing tool," says Perry. "Without it, people could just be exchanging dry bits of information, not keeping each other informed of their ideas or emotional processes. It's all about practice, not just doing it once. [Grayson and I] did it formally for about two or three years."
Stress, meanwhile, isn't all bad. "Good stress... is what we need for personal development and growth," writes Perry, who – as if to prove it – ran the London Marathon in 2008. "It was the best thing I ever did," she says. "It's comfort-zone expansion. I've never been sporty, but every year when I saw the Marathon on the telly or went down to the river to watch it, I couldn't stop crying. I found putting so much effort and training into something very moving."
The book is dedicated to Perry's father, now in his 90s, who still lives in Warrington, in the house where both he and his daughter grew up.
"He was born in one world war, and a major in another. I dedicated the book to him because I wrote it in a bit of a hurry and couldn't visit him as often. So it was a present; an act of love. I don't know if he'll read it."
Perry was born Philippa Fairclough in 1957. As a teenager at boarding school, she had undiagnosed dyslexia. Her parents, thinking her unacademic, sent her to a finishing school in Switzerland. "I saw it through," she recalls. "Not like Lady Di, who only lasted a month! I learned to ski and speak French."
She was married and divorced and worked for law firms and McDonalds, before going to art school as a mature student. The products of her art practice are as evident around the house as Grayson's: she painted the pictorial tiles in the kitchen, and created the intricate fireplace, which closely resembles some of the work in her husband's recent British Museum exhibition. "I made it in 1991," she explains. "So I was first! But I got bored of sitting in a room all by myself every day with Radio 4 and powdered milk. I like being with people." She met Grayson on a creative writing course in 1987. Their first date was at a transvestite club – and, yes, "When we were first together and he was poor, we did share clothes. He liked my Jaeger suits."
A round the same time, she became a volunteer with Samaritans. "I'm a child of the 1950s and we didn't talk about things; we just got on with it. I thought I was volunteering for the Samaritans because I could give back something to the community. But with hindsight I think my motivation may have been finding out if it was safe to talk about feelings. I listened to a lot of people, and it really seemed to work. So I thought I might give it a go myself, and went to therapy. It helped me enormously. I became very interested in the process – so then I trained to be a therapist. I felt inspired to see if I could help other people."
The Samaritans also taught her that people don't always recognise the source of their own unhappiness. "When I was a volunteer, a lady rang asking for advice about good second-hand shops in the area, 'because we've got a lot of gentlemen's clothes that we don't need any more.' Of course, you know that isn't the issue, so you ask: 'Why do you have all these clothes? Oh, your husband died... What sort of man was he?' To her the problem is that she has all those clothes, but of course that's not the real problem. Why she called Samaritans and not her neighbour, only her subconscious can say."
In 2010, Perry published her first book, Couch Fiction: a funny, frank graphic novel about a therapist and her patient that sought to demystify the psychotherapy process. She gave up her practice to focus on writing and now has a monthly column in Psychologies magazine. She's also an accomplished tweeter. "Twitter is great for the anxious narcissist who likes a bit of reassurance from time to time," she says. "It's a form of self-soothing."
As well as publishing Perry's book, the School of Life offers a therapy referral service for anyone who feels they need further help remaining sane. "Remember: see a psychotherapist and you might feel better," she warns, "or you might just feel broke... Every case is different. Every therapist is different. You can't say 'I tried therapy and it didn't work'. You might just have the wrong therapist." But when it works, she says, it really works: "The relationship with your therapist could be the most important relationship you ever have. Sometimes a friend needs tough feedback but you're not in a position to give it to them, and they don't want to jeopardise the friendship by doing so. But a psychotherapist could."
'How to Stay Sane' is published by Macmillan on 10 May, £7.99