Causes of Mental Illness

Many people use fantasy as a way of coping and it isn't necessarily unhealthy. It is a defense mechanism. It becomes a problem, as any thought might, when it is an obstacle to "normal" life. This judgment of "normal" is usually determined by the individual. However, it may be determined by those around him as well.
I see that one of your tags is "schizophrenia." There are many different theories as to how schizophrenia begins. Neurotransmitter peculiarities seem to be the most likely. Fantasizing is not considered a cause in regards to schizophrenia or psychosis. Actually, delusions are not a way (nor do they begin as a way) of coping with reality. They are, for the people experiencing them, more troublesome and stressful than reality itself. In this way, they are the opposites of fantasy and coping.

Nice answer, Flesh .

I think that anyone who goes into his/her "other reality" to that degree would need the time and space to do that. Work, family and this world would be left behind - a total detachment. To protect this person and meet corporal needs, it would take institutional protection.

The rest of us fantasize or day dream, but we still function in this world, hurtful as it might be.

flesh out-
Thank you.

As to my tags, I don't know how they are created. Not by me.

Depression and stress are the most and common seasons for mental problems. In this situation person feel him self alone. and stay lazy all the day. He dose not take interest in any tasks.
This situation can be come over by increase the motivation of that person and he have to keep busy him self in a whole day.