Am I depressed?
When I was depressed I didn't realise. I thought I was just exhausted and stressed from the demands of a young baby. It was in fact more than just the baby blues as life felt flat and joyless. It took my husband and mum to persuade me that I really needed to see a doctor and what I was experiencing was depression. They were right.
I don't know why I didn't realise at the time but it's not uncommon. It's not always easy to identify. Some people don't know what depression is like and others don't want to admit that they have it, even to themselves.
"It can take some time to figure it out," says Dr Antonis Kousoulis from the Mental Health Foundation. "You don't wake up one day being clinically depressed, it develops over time and sometimes takes time for you to notice it."
He says: "Close friends or family are generally good allies in identifying it. Parents often see changes of behaviour in their children."
There may be different reasons why people aren't always aware.
"It could be down to a lack of knowledge that they don't know what the actual signs and symptoms of depression are," says Windy Dryden, emeritus professor of psychotherapeutic studies at Goldsmiths University of London and author of Overcoming Depression.
"Alternatively it could be that to admit to depression may feel like publicly admitting to weakness as you feel like you have to be strong. So it's a shame based blocking," adds Windy.
No reason to be depressed
Depression can be brought on by an event or situation. A bereavement or break-up can trigger it but often there's no so-called reason for it.
If to all extents and purposes you have a good life, nice family, great job etc. because you have no obvious reason to be depressed it may not always occur to you that you are. Depression doesn't work like that. To the outside world you may seem to be the luckiest person in the world but you can still be depressed.
Hard to talk about
You could put your constant tiredness, irritability or anger down to working too hard or other people's foibles. "If your family culture is one where negative feelings shouldn't be talked about you may not feel allowed to admit to being depressed," says Windy.
One in five people will have depression at some point in their lives so it's a very common condition but that doesn't always make it easy to admit to. " Mental health is still a taboo topic and often people feel unable to talk about their thoughts and feelings," says Stephen Buckley from the mental health charity Mind.
Signs and symptoms
A depressed person doesn't look a certain way or even exhibit exactly the same symptoms as others with depression. You can still carry on living an outwardly "normal" life and be depressed.