It was the worst experience of my life. More terrible even than watching my wife die of cancer. I am ashamed to admit that my depression felt worse than her death but it is true. I was in a state that bears no resemblance to anything I had experienced before. It was not just feeling very low, depressed in the commonly used sense of the word. I was seriously ill.
Professor Lewis Wolpert, CBE, Fellow of the Royal Society of London.
(Malignant sadness: the anatomy of depression, London, Faber and Faber, 2001)
Some people refer to it as being like disappearing into a black hole. Sir Winston Churchill described depression as 'the black dog' and the writer William Styron wrote of 'darkness visible'.
If you are seriously depressed you will know that it is difficult to communicate how bleak, how painful and how disabling your depression is to someone who hasn't experienced the problem personally. What you can say is that it is NOT the same as feeling a little sad or 'blue'. As Professor Wolpert describes above, it is not even the same as normal grief. In fact, according to medical experts , depression disrupts a person's life as much as other serious illnesses such as multiple sclerosis, severe asthma or deafness.
"Natasha, a 20 year old student, is a typical example of someone who is depressed.
She has been feeling very down for the last few months. She normally has good relationships with her friends, but now she find that she can't talk to them about how hopeless and meaningless her life feels to her. They no longer drop in to see her because she is so withdrawn. She has lost weight because she is not eating properly. She wakes up at 3am in the morning and can't get back to sleep.
Natsha can't keep her mind on her study and finds making decisions difficult. She can't seem to enjoy anything either. Most days it is a huge struggle just to get to university. When she can get herself to a lecture, she comes home and just goes to bed or watches TV. She no longer feels like playing the flute, although it used to be her favourite pastime. She wants desperately not to feel this way, and her future looks very bleak to her. She doesn't know what is wrong, or how to fix herself up."
Natasha is not alone in her distress. The chances are that her neighbour, someone else in her family, her lecturer and famous people she has read about have also experienced depression.
We know that about 6% of Australians will suffer from depression in any one year. 
Not everyone will experience exactly the same problem. But, some problems are common in depression. These usually involve changes in feelings, thoughts, physical well being and behaviour.