Q. My mother is generous, clever and loves her two sons (I'm the younger at 35), but her Mary Whitehouse tendencies are getting worse: loudly proclaiming her loathing of immigrants, hatred of anything she disapproves of, fury at any bad language. She's turning more crabby and bitter as she grows older. I finally lost my rag with her after a dreadful visit. My father admits she's getting worse. I can see he's very unhappy but perhaps he is honour-bound to stay with her. Would therapy help her? Yours sincerely, Malcolm

A. The people in this scenario who need therapy, it seems to me, Malcolm, are you and your father – to help you try to come to terms with accepting a woman whose ideas clearly are so different from your own. You describe her very well – and I'm sure everyone who's reading this knows exactly the sort of woman you're talking about. Indeed, some of my own ageing friends, who were reasonably open-minded and liberal when younger, are turning more and more rigid in their views and can do nothing but bang on about the state of the world, muggings in the street, the ghastly youth of today, and so on. It's horrible to witness, and a lot of teeth-gritting and changing of subject has to be employed to make being in their company bearable.

But it's one thing for friends to rage about immigrants and demand that one agree there's a case for bringing back hanging, and quite another when it's a close relative, or someone you love, doing it. The fact that they are so close means it is that much more difficult to separate yourself from their views, and you feel that, as you have genes in common, perhaps they, or other people, might think you have views in common as well.

There is no way, Malcolm, that you can change her. And it sounds as if she is, if anything, going to get worse rather than better. But there are some techniques you can use when being with her that might make your life – and hers, actually – a little easier.

When she next tells you how wonderful Sarah Palin is, or declares that life was far better for everyone when she was young, try to fantasise that she has a notice around her neck, invisible to everyone except yourself, which reads "Madhouse Inmate" (or, if you prefer, "mental institution" or "loony bin", whichever suits you).

Another tip is to declare certain topics off limits. You could say: "Mum, we disagree about immigrants, global warming, the morality of Posh and Becks, and religion, so let's save ourselves a lot of misery and just not talk about them, OK? From now on, those subjects are out of bounds."

If she refuses to sign up to such an agreement, then simply agree with whatever view she's holding. Don't argue. Just say: "Yes, of course if we flogged people and chopped their hands off if they did wrong, the world would be a better place." If your agreement simply irritates her, say: "Yes, Mum, you certainly have a point there" – which is quite true – and move on to talk about the weather, or some more interesting subject about which you do agree.

It's a shame you have to resort to such tactics, and obviously it would be nice if you could have sympathetic conversations with your mother, but her intransigence is either a sign of age – which she can't help – or perhaps terror in a changing world, for which she is to be pitied rather than condemned.

Be grateful, too, for her love, and also for the fact that her rigidity is teaching you a valuable lesson for old age, which is to try, mentally, to keep as flexible and tolerant as possible till the day you drop.

Readers say

Her world is changing

She can't help it! She is old-fashioned and has old-fashioned views. We live in an ever-changing world, and while she doesn't agree with some of the changes, you can't just send her to therapy! I am sure there are things about society that you and I don't particularly like, but are we being sent for therapy? No.

Ian laird, Wirral

Put it in writing

You might be powerless to make your mother change some of her views, but you can influence the way she expresses them. You and your brother should get together on this. If your mother still clearly loves you both, she will be concerned at the thought of losing you both. Don't threaten this, but it might be a good idea to "mark her card" as to what you will and won't put up with. Put this in writing and give her the chance to read it and reflect just how much she is upsetting you. Establishing boundaries and rules can work with errant children; why not with parents too!

Linda Bateman, Worthing

She may be depressed

My mother makes Margo Leadbetter look like Pollyanna, so I empathise. Your mother sounds as if she's always been a forceful character. However, if you have noticed a greater level of anger and irrational outbursts, it could be a sign of depression or early dementia. Let your dad know you are concerned for both of them. He may or may not want your help, but will be glad to know you are there if needed.

Christina Burton, St Leonards, East Sussex

Don't be a prig

What a prig Malcolm sounds, and rather sinister. He doesn't agree with his mother's views, his father says she's getting worse so Dad is unhappy and staying out of duty, and Mum needs therapy. Why: to correct her thinking? Malcolm's 35? He sounds 15. He should grow up and realise that his mother is perfectly entitled to hold her views.

Sheila Baynes, Southampton

What's really bothering her?

I'm afraid a lot of people as they get older become disillusioned with the world, and tend to grumble. In your mother's case, things may go a little deeper. She may be frightened of getting older. Try to get to the bottom of what's really bothering her. Is she bored? If so, encourage her to try hobbies or charity work. I'm sure your father isn't staying merely out of duty, but if that is the reason they are still together, that might cause her frustration.

Speak to them separately to find out what's really going on. Explain gently to your mum that her outbursts upset everyone. Think of ways to improve the quality of life for both of them. If your father is retired, they could be spending too much time in each other's company. If so, suggest they develop separate interests. Equally, if your father is out of the house a lot, that could cause resentment. You can't really get too involved in their marriage. But I would tell your mother that you don't visit her to hear her moan and groan, and if she carries on you will leave. If you quietly walk out each time she starts, she may get the message.

Kate Yarrow, Leicester