Language is always revealing. We talk about being mired in our problems. A mire is a swamp or bog. The image is of being trapped, sucked in, impossible to extricate. Quicksand is the most terrifying form of mire.

Steve Hayes, an eminent psychology professor in the US, uses a metaphor about quicksand to introduce an approach to healing he calls acceptance and commitment therapy (ACT).

When we're stuck in quicksand, our immediate impulse is to struggle and fight to get out. But that's exactly what you mustn't do because as you put weight down on one part of your body (like your foot), it goes deeper.  So the more you struggle, the deeper you sink – and the more you struggle. It's a no-win situation.

With quicksand, the way to survive is to spread the weight of your body over a large surface area by laying down on the quicksand. It goes against all our instincts to do this - to get into as much contact as possible with the very thing that is threatening us. But that's exactly what we have to do.

It's the same with distress. We struggle and fight against it. But perhaps we've not considered just letting it be, of being in direct contact with the distressing thoughts and feelings. If we did, we'd find that we'd get through it and survive more effectively than if we'd fought and struggled.