A person in this state is at loss from reality and may find it very difficult to speak in coherent sentences. The voices and delusions are very real to the individual. These symptoms are called positive because they are added onto the individual's experience and behavior.(DSM-IV).
Negative symptoms are deficit symptoms where experience and behavior is taken away. Examples of negative symptoms include loss of motivation, flattened emotions, withdrawal from an active social like, poverty of speech, loss of former interests and pleasures Loss of abilities like perception, memory, abstract reasoning, alertness, and planning fall also into the negative symptoms under cognitive abilities. Depression is also common among negative symptoms. These symptoms become more apparent once the positive symptoms have responded to medication.(DSM-IV).
The normal requirements for a diagnosis of Schizophrenia are the clear presence of two or more positive or negative symptoms for a duration of at least one-month. For a significant portion of the time since the onset of the disturbance, one or more major areas of functioning such as work, interpersonal relations, or self-care must have declined. Continuous signs of the disturbance must persist for at least six months including one month of symptoms. Any effects of a substance or a general medical condition cannot cause these symptoms. (DSM-IV).
Although a person may be diagnosed with schizophrenia, it is not always effective to stop there with the diagnosis. There are many forms in which the disease can manifest itself. The most commonly found in most parts of he world is the paranoid type. It is dominated by positive symptoms, which are relatively stable and often paranoid. Delusions are usually accompanied by hallucinations, which are particularly auditory in origin. Negative symptoms are often present but are usually not distinct. (DSM-IV).
Another subtype of schizophrenia is called catatonic.