Despite the movie Me, Myself and Irene, as well as the quote that "I used to have schizophrenia, but we're okay now," schizophrenia has nothing to do with Dissociative Identity Disorder (DID, commonly known as multiple personalities).
The reason many people think it has to do with DID is because they think that if you have multiple personalities, you talk to yourself. This is not true. Most people with DID don't even know that their alters exist. But I'll go more into DID later.
If you would like a good example of what schizophrenia really is, watch the movie A Beautiful Mind.
Now that we've cleared that up, on to the fun stuff:
We all think to ourselves. It keeps our brains--and our lives--organized. We all feel paranoid at times. It's a natural defense/protection mechanism. We all have felt defensive of something that we consider to be ours. As we accomplish certain tasks in life, we may feel a sense of grandeur associated with said accomplishment, and that's perfectly okay.
But what happens when some of those things get out of hand...and out of our control?
Welcome to schizophrenia.
There are a few main types of symptoms that mental health pros look for in someone who might have schizophrenia. One main symptom is hallucinations. About 20% of hallucinations experienced by someone with schizophrenia are visual, 70% are auditory, and 10% are another type (smell, touch, etc.).
Since it's the auditory hallucinations (hearing something that isn't really there) that most people think about when they hear of someone with schizophrenia, I'm going to focus on that part of the hallucination category.
Everyone talks to themselves in their heads. It's called self-talk. As children, we talked to ourselves out loud while we were learning how to talk, but as we grew older, that self-talk went internal. If you were to have an MRI, a certain part of your brain called Broca's area would light up while you were thinking to yourself.
Now here's the kicker: There's another area of the brain called Wernicke's area that's in charge of hearing.
So, the latest theory is that people with schizophrenia who are having auditory hallucinations are actually hearing their own self-talk, but not in their own voice.
Generally, if you hear someone talking to you, do you think back your answer? Of course not. You talk to the person. This is why it looks like people with schizophrenia are talking to themselves; according to this theory, they are.
How would it be if you were hearing a strange voice and couldn't get it out of your head because it was, in fact, your voice?
That would be enough to drive anyone crazy.
But wait. There's more.
Delusions. These don't just show up every once in a while. These delusions are thoughts that the person will organize his/her entire life around. There are generally three types of delusions associated with schizophrenia: Delusions of grandeur, delusions of persecution, and delusions of jealousy (defined as the need to be vigilant in guarding something). One may have only one of these types of delusions or he/she may experience all three.
Other delusions of grandeur may be associated with the idea that you are a high-profile secret service agent trying to solve a case, the president of a country (the "real" one is either a phony or an impostor), or that you have made an amazing discovery that others just don't seem to understand.
The woman I mentioned also had the symptoms of persecution. She fully believed that her next-door neighbors were international spies who had attempted to kill her on multiple occasions. This type of delusion leads to extreme paranoia: every time her neighbors walked past her house, she was convinced that they were scoping out their next attack. When she saw her neighbors across the street go to a dinner party at "the enemies'" home, she decided that they had been accepted into the spy ring. To protect herself, she had a 6-foot high cement wall built around her entire property with a metal, windowless door as the only way in or out.
In the place where this woman lives, treatment options are minimal and, for the most part, practically non-existent simply due to lack of resources and information. How would it be to live a life in genuine fear of everyone around you?