Depression is like living behind a dirty window. You see life going on on the other side, but you are cut off from it. The colours are dimmed. The sounds are muted. Whatever joy or warmth you see on the other side of the window does not cheer or warm you. You feel completely isolated.

The other cruel thing about depression is that it offers you no hope. It’s quite different from sadness.  If you feel sad about something, you know what needs to happen for you to be happy again. Something needs to change, or you need to mourn something, but you have a hope, at least a hope, of being able to pass to the other side of the window. With depression you feel no hope. To anyone else your life may seem fine, even perfect. But to you it’s all grey, all hopeless, and you have no idea why.

Sometimes depression is a constant. Sometimes, though, it comes and goes. This can be even worse, as we never know when it may strike. One moment everything is fine, then the next morning the whole world is grey again. We are cut off from friends, family or anyone who could help. We are cut off from our own power to help ourselves.

But there is hope, if you know where to look. It’s probably not where you think. And, crucially, you may need help to see it. Let me give you an example.

Sarah was a civil servant in her early thirties. To the outside world her life seemed great. She liked her job, and her managers were supportive. She had a loving boyfriend, and they were thinking about starting a family. Her parents were helpful.

But in spite of all this, Sarah was persecuted by attacks of depression. Sometimes they lasted half an hour, sometimes a week. She had no idea what caused them, or how long they would last. She had no way of rescuing herself from them. She lived in fear of the next attack.

The attacks were getting worse. They were more frequent. The depression was deeper, and lasted longer. It was starting to affect the rest of her life. She was having to take more and more time off work. Her boss was sympathetic but Sarah knew she couldn’t rely on his sympathy for ever. Her boyfriend was talking about having a baby, but Sarah just didn’t feel ready. He was disappointed, but  understanding. Sarah feared, though, that he couldn’t wait forever. Neither, aged over 30, could she.

When she consulted me, Sarah’s case seemed baffling at first. We looked for negative thoughts, the cognitive explanation. There were none. We looked at her present situation, but there seemed to be nothing there to explain the problem. Nothing in the past either. Nothing being repressed or suppressed.

Then I told Sarah “Ask your parents if anything happened in the family when you were small, particularly something they didn’t tell you about.” This produced a big surprise.

It turned out that, when Sarah was three, her mother had been seriously ill in hospital. Her father was convinced she was going to die. Thinking to do his best for the family, though, he hadn’t told Sarah anything about it. Sarah had unconsciously picked up his fear and panic. Her mother made a full recovery and life continued happily as before. The trauma, however, remained with Sarah, more powerful because neither she nor her father had ever talked about it. They had not even realised what had happened.

Unearthing this buried trauma was decisive. The attacks of depression immediately became less frequent, and less vicious. After ten sessions the treatment was complete.

The lesson is that we know very little about what goes on in our minds. Most is unconscious, and more powerful for that very reason. By knowing where to look, with the right help, we can bring the buried trauma to the surface and free ourselves from it.