Somebody who has schizophrenia is experiencing a disorganization of a variety of brain functions. In fact, some are very conspicuous; they are the distinctive symptoms of schizophrenia. The obvious one is making inappropriate connections or misinterpretations. A very common problem for someone with schizophrenia is hallucinations. You're actually getting messages from within the brain, but they appear to be coming from outside. Then associated with hallucinations are ideations, where you think that other people are communicating with you, telepathically giving you ideas, or thinking that your faults are known to other people.
Then the other thing that's very central to schizophrenia is that the actual thinking itself gets disorganized. It's what we call "thought disorder." For example, feelings get disconnected. In schizophrenia, these thoughts often begin without the usual kinds of triggers; so you get angry or depressed or anxious or bewildered without the sort of things that would normally set someone off. Sometimes these feelings occur spontaneously or as a reaction to the ideational changes or hallucinating experiences. So, your thinking and your feelings now become disorganized and often disconnected.
There are also often physical changes—disruptions in appetite and sleep patterns—so the disease seems to affect the brain very broadly.
What are the goals of treatment in schizophrenia?
The primary goal of treatment is to reduce what are called the "positive symptoms" of schizophrenia: hearing voices, the thought disorder and other problems in thinking, changes in mood. Medication should help with all those things.