It was Winston Churchill who described his depression as a black dog. He was a man who liked cats.

My brother has a black dog. Her name is Shiraz, and she is a collie/shepherd/greyhound mix of faithfulness, affection and gentle fun. Shiraz is about as far away from depression as you can yet. In fact, she's a great help to my brother when he feels down – because there's nothing like the love of a good dog to make you feel better about yourself.

While that video you watched last week described pictorially how depression feels, many of you animal lovers out there felt it was very unfair to real black dogs. And you may be right. A fellow Moodscope blogger wrote about Oscar, the black therapy cat. There are many animals out there helping people when they suffer from depression. Some of those animals happen to be black.

The fact that the image was a dog was not that important. The message was about giving the depression a shape. The dog is a convenient shape as it is recognisable and familiar. It then makes sense that everyone has one of these shapes with them – just in lots of different breeds and sizes.

So what shape does yours take? Some time ago I wrote about my dirty grey leviathan which periodically swallows me up for days, weeks, months at a time.

Picturing it as a shape or animal in my mind helps me be less scared of it. In fact, because of the power of our minds, I can change its picture so that it becomes almost a cartoon, with rolling eyes and a swishing tail. Like the man in the video I can start to tame it, to reduce it in size. I can take steps to avoid its worst effects.

So picture your "monster" and then start to make it less scary in your mind. The days still come when it gets the better of you, but it's much easier to fight what you can see – even if you see it only in your mind's eye.