Sometimes depression gets bad so that the person can’t sleep properly, loses his or her appetite and doesn’t enjoy anything.
Sometimes the person worries so much that he or she doesn’t go out, can’t sleep and feels anxious all the time that bad things will happen.
Sometimes the person gets thoughts about keeping everything in order and has to do things, like activities such as too much washing, which he or she may believe will stop bad things from happening. These are called obsessive thoughts.
Sometimes the person can behave in a way that seems as if he or she doesn’t care about anyone else, and just wants to have things their way. This might mean that the person upsets other people but it may be that really he or she feels very unhappy inside him or herself, without really knowing why.

Sometimes when a person gets ill things can go beyond what we can normally understand. A person’s behaviour, as well as what they say may seem to just not make any sense.
The reason this happens is usually a mixture of different things – such as the way people are built or made up (like what they inherit in their genes), but this is always affected by how they live their lives (including stresses and strains such as losing a job or splitting up with a partner), as well as the kind of life they live when they are growing up.) It can also happen because their mind or brain gets overloaded – that is it cannot cope with or manage all the things going into it. We don’t exactly know why this happens to some people, but there are some ideas detailed in the other sections of this website.