Some months ago, I had bad Botox. My eyebrows were pushed so far down that I looked constantly angry. I felt it, too. “Let it go,” said a friend, tired of my complaints. Well, I would have, except that my face couldn’t. ”I feel angry all the time,” I moaned to my therapist. “Hardly surprising,” she said. “If we want to lift our spirits, one of the ways we can do that is to smile. The opposite is also true.”

She’s right. Study after scientific study shows that controlling our facial expression controls our mood. Smile and your soul smiles with you. Certainly, a smile helps defuse a potentially toxic situation, but there I was, trapped in a paralysis of hostility — for months. I got into fights without even trying. As I suffer from a depressive disorder, my interest in maintaining a steady emotional temperature is not entirely altruistic. Stress, anger or high levels of arousal can precipitate a depressive relapse.

The point, though, is not to release it by screaming and shouting, but by gently persuading the mind to see things differently. That’s why all the newest forms of cognitive behavioural therapy (CBT) incorporate Buddhist elements of mindfulness and compassion. When the Buddha said, some 3,000 years ago, “life is suffering”, he meant that our minds create our suffering. Smart guy. We accept that we have difficult emotions, but just because an emotion is difficult or powerful, it doesn’t mean it’s important. Nor does it mean we have to act on it.

Anger, of course, is unavoidable. It’s one of the primary emotions. It’s a woman shouting as her small child heads for a busy road. Healthy anger is sharp, clean and commanding. And it’s over in a matter of moments. Toxic anger is the chattering monkey sitting on our shoulder, going over and over some slight grievance until it is magnified into rage.

Consuming, corrosive and incredibly bad for our physical and mental health, it is often about an inability to communicate. If we are unable to express our needs, we stuff our feelings down. Resentment builds on resentment (most anger is cumulative, which is why it’s best to nip it off at the source) until we are walking time bombs, ready to explode at the tiniest provocation, or so frightened by the violence of our feelings that we dull them with alcohol, drugs or food. It’s also a classic cover for fear — the fear of being hurt or destroyed. Its appeal is in its energy — it makes us feel, at least momentarily, that we are powerful and in control.

Meditation and yoga are helpful (both physiologically and psychologically, they are self-soothers) as are any of the compassion- and mindful-based CBT therapies, because they teach us not only to challenge our automatic negative thinking, but to forgive ourselves. Oh, yes, and smiling helps, too. It doesn’t matter if you don’t feel it. Do it often enough and you will. As they say in the recovery movement, just fake it till you make it.

Helpful reading: The Compassionate Mind by Paul Gilbert (Constable £20); Full Catastrophe Living by Jon Kabat-Zinn (Piatkus £20)