So what can we do to stop the rumination that feeds painful emotion?

When trying to change something in the moment, purely using a mental concept in our heads to re-focus on something new can be hugely difficult. Usually, an active approach has a much better effect.

When you notice that you are sliding down the slippery slope of rumination, try a firm hand pushed out in front and one word, ‘Stop!', quickly followed by physical movement, such as standing up and moving away from the position you are in. Change activity for a moment, or even just walk around or step outside for a few minutes, whatever is possible at the time. Physically moving your body can help to shift your mind when it is otherwise very difficult.

Another very simple way to redirect things, when we are not sure of the way out, is a question: ‘What would I do if I was at my best?' Now, if you are experiencing dark times and depression, you cannot expect yourself to be doing whatever you would be doing at your best. But you can create a mental picture of the direction you want to move in. So, if I'm sitting ruminating on a painful experience in my life and have lost several hours to that churning, I can ask myself that question. The answer may be, ‘I would stand up, take a shower and put some nice music on that lifts my mood. Or perhaps I would pick an activity I enjoy that absorbs my attention.' Dr. Edward Ned Hallowell says, “don't feed the demon” – when you're ruminating, do ANYTHING else. Clean your room. Go for a walk/run. In fact, do any kind of exercise. Wash the dishes. Do anything but sit and ruminate – keep trying to distract yourself.

For anyone who is prone to rumination, time alone opens up the gates of the arena for the thoughts and memories and subsequent emotional pain to come flooding and start circling your mind.

Human connection is quite possibly the most powerful tool we have to let those thoughts exit after a few rounds. Friends or a therapist will listen carefully to each one. But they can be great at holding up a mirror to our minds by reflecting back to us what they notice. They help to build our self-awareness and provide prompts or clues to call a stop to the rumination and shift to something new and more helpful to our well-being.

Gratitude.  practice is another simple way to get used to turning your attention. This can be something big like your loved ones, or it can be a small detail of your day that you appreciate, such as the taste of your coffee as you sit down to work. Now, this sounds almost too simple to be effective, but every time you engage in gratitude, your brain is getting practice at turning its attention to things that create pleasant emotional states. The more practice you get - the easier it becomes to use that in other situations.