You often mention addictive personalities and depression, which sounds just like our best friend, who is having an affair with her married boss – the only person she has ever had sex with. She’s kind, clever and gorgeous-looking, but can’t believe any half-decent man could like her. She is obsessed with him, dresses up in high heels (he has a shoe fetish) and has only anal sex, so he won’t feel he’s “cheating” on his wife. She is totally professional (other than getting smashed every Thursday and Friday night), and would be deeply ashamed if her colleagues found out. Her family would also be disappointed, but they may be part of the problem: her mother has a weird relationship with food and is obsessed with the idea that her daughter might get fat. Our friend tries to hurt us, saying he understands her (as if we don’t) and that she “tells him things she would never tell us”. She used to self-harm, and we are worried she is cutting again. She scoffs at counselling, saying: “It’s my life, let me get on with it.” We tried tough love, but she was cold and emotionless. We are at our wits’ end.

I can see you love your friend very much, and want the best for her, but I think you’re going about this in the wrong way. In your longer letter, you sound like overanxious mothers. It seems she already has one of those at home, so criticising the company she keeps is going to do more harm than good.

Her cold and emotionless response is classic withdrawal. If her mother is locked into an eating disorder and constantly fretting that her daughter is going to get fat (or “not be good enough”), she may have grown up with a constant feeling of being disapproved of, so her response to criticism will be to shut down.

I know your intentions are good, but don’t you think that perhaps she might be right when she says it’s her life and she’d like to be allowed to get on with it? The married boss may be a creep, but he’s a creep with one particular virtue: he lets her be herself. That, no doubt, is why she feels he understands her, and she is able to tell him things she would never tell you. The more you show disapproval, the more she will run towards his dysfunctional love and away from your care and concern. I doubt she is trying to hurt you by saying he understands her better. I suspect it’s more that she’s telling the truth – He probably does.

Trying to make her conform to your image of what is right, as well as discussing her behind her back (which she will be only too aware of after the tough-love intervention), will shame her. For some reason, I feel she’s carrying a load of toxic shame from her childhood. Self-harming, punishing sex and binge-drinking are shame-based behaviours – by which I mean they indicate a lack of self-respect or self-love. If we are shamed as children, we may believe we are not worthy of kindness, even our own. Because she doesn’t feel good about herself, she hitches herself to a man who doesn’t feel good about himself, either. The two of them are united by a mutual understanding. Often, we are drawn to people because, at an unconscious level, we recognise the damage in each other and confuse that recognition with passion or a kind of soul mates’ love.

No doubt you think she is prepared to indulge in sodomy and foot fetishism because he has some sort of hold over her, but you do have to be willing to engage. I’m guessing the only response he’d get from you two would be the slamming of a door. It seems she has a distorted perception of what’s good for her, as well as low, shame-based self-esteem – hence her inability to think that any half-decent man could be interested in her.

If you want to help her, you need to love her, not shame her. You don’t have to make a huge show of approving of her lover, but you do need to make a huge show of approving of her. To have any effect, you must win back her confidence. Right now, I expect she’s desperate to avoid you. I suspect she needs more help than you can give, but she is the only person who can make that decision. If she reaches a state of sufficient pain, she may seek help; in the meantime, all you can do is offer love and compassion, and avoid moral or emotional judgments. She may get badly hurt by this man, but it is not in your power to stop that. We have to learn from our own mistakes. It’s the only way.

All you can do is put in place some damage limitation by building up her confidence and self-esteem, constantly assuring her that she is indeed lovable, and worth more than a tawdry affair with a man acting out his own dysfunctions. I’m going to recommend a book that may help you to understand why she behaves as she does, as well as show you loving and productive ways in which to take the best possible care of her.

Healing the Shame That Binds You by John Bradshaw (Health Communications £10.99)

If you have a relationship question for Sally, e-mail sally.brampton@sunday-times.co.uk. In case of publication, names will be withheld. We’re sorry, but Sally cannot answer letters personally

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