I think most people talk to themselves in their heads. When you don't know you are talking to yourself and not a perceived outside entity, that is when you may have a problem, particularly if said entity is mean or tells you to do bad things.
Even "normal" talking to yourself in your head can be detrimental to your mental health, such as with Pure-OCD. When thoughts tend to be negative and it becomes impossible to break a negative thought cycle, it is very hard on the sufferer. However, unlike delusional people, they know the thoughts belong to them, which can cause even more distress while they wonder if it is a reflection of who they are.
Even "normal" talking to yourself in your head can be detrimental to your mental health, such as with Pure-OCD. When thoughts tend to be negative and it becomes impossible to break a negative thought cycle, it is very hard on the sufferer. However, unlike delusional people, they know the thoughts belong to them, which can cause even more distress while they wonder if it is a reflection of who they are.
