paranoid-type schizophrenia: may have delusions that one or more people are plotting against them or their loved ones. It is difficult or impossible for others to convince them that they are not the target of a plot. People with this condition may spend a lot of time thinking about how to protect themselves from the person or people they believe are trying to harm them.  Is marked primarily by delusions that follow a theme, like persecution or grandeur. Auditory hallucinations may accompany a delusion and are, therefore, usually related to its theme. Symptoms common to other subtypes, like disorganized speech and flattened affect, are not usually prominent in episodes of paranoia, but anger, irritability, and extreme anxiety are. People suffering from paranoid delusions become particularly preoccupied with them and may be especially prone to violence.


disorganized-type schizophrenia: type of schizophrenia in which behavior is disturbed and has no purpose. Is marked by disorganized speech, behavior, and flattened affect is particularly disruptive. The disorganized episode often features fragmented speech and inappropriate or unexpected behavior that does not reflect ideas expressed verbally. Strange mannerisms, gestures, and surprising behavior are common. This type of schizophrenia typically causes significant dysfunction in daily life, self-care, and interaction with others, as well as notable thought disturbance and loss of goal-directed behavior. People in the midst of a disorganized episode show no catatonic signs.


catatonic-type schizophrenia: People with catatonic type assume peculiar postures and are usually speechless. They may be both rigid and motionless, or they may seem agitated and move around excessively, but always without external stimulus. Catatonic people may also have strange facial expressions, may mimic the behavior of others, and may repeat words that others say. Catatonic behavior is also seen in mood disorders, like bipolar disorder and major depressive disorder, and occasionally in diseases of the central nervous system, like Parkinson's disease.


positive symptoms:
* hallucinations and illusions
Hallucinations are perceptions that occur without connection to an appropriate source. Although hallucinations can occur in any sensory form - auditory (sound), visual (sight), tactile (touch), gustatory (taste) and olfactory (smell).
* delusions
Delusions are false personal beliefs that are not subject to reason or contradictory evidence and are not explained by a person's usual cultural beliefs. Delusions may take on different themes.
*Disorganized speech/thinking
Disorganized speech/thinking, also described as thought disorder or loosening of associations, is a key aspect of schizophrenia. Disorganized thinking is usually assessed primarily based on the persons speech. Therefore, tangential, loosely associated, or incoherent speech severe enough to substantially impair effective communication is used as an indicator of thought disorder by the DSM-IV.
* Catatonic behaviors
Catatonic behaviors are characterized by a marked decrease in reaction to the immediate surrounding environment, sometimes taking the form of motionless and apparent unawareness, rigid or bizarre postures, or aimless excess motor activity.


negative symptoms:

*Affective flattening is the reduction in the range and intensity of emotional expression, including facial expression, voice tone, eye contact, and body language.
* Alogia
Alogia, or poverty of speech, is the lessening of speech fluency and productivity, thought to reflect slowing or blocked thoughts, and often manifested as short, empty replies to questions.
*Avolition
Avolition is the reduction, difficulty, or inability to initiate and persist in goal-directed behavior; it is often mistaken for apparent disinterest. (examples of avolition include: no longer interested in going out and meeting with friends, no longer interested in activities that the person used to show enthusiasm for, no longer interested in much of anything, sitting in the house for many hours a day doing nothing.)

differnece between a halucination and a delusion:
Delusions are a symptom of some mental disorder, such as schizophrenia, delusional disorder, schizoaffective disorder, and schizophreniform disorder. Hallucinations, on the other hand, tend to only appear in people with schizophrenia or a psychotic disorder.


cognitive symptoms of schizophrenia:

• Difficulty maintaining attention The inability to maintain focused attention makes people with schizophrenia seem spacey or “out of it.”
• memory problems
  Schizophrenia often effects working memory, which is the kind of memory you use to keep things in your head for active processing, like the digits of a phone number you’re about to dial.
• Difficulty planning and structuring activities
  Caused by reduced executive control. Executive control is the mental process that allows us to identify the steps needed to complete a task and then execute them in a proper order. Executive control also allows us to suppress our response to distractions in order to get something done.
• Lack of insight
  People with schizophrenia have a specific cognitive blindspot that prevents them from understanding that they are ill. This means that loved ones and caregivers should remain as vigilant as possible to help the patient maintain the routines of treatment in order to control symptoms.

avolition:
 Avolition is the reduction, difficulty, or inability to initiate and persist in goal-directed behavior; it is often mistaken for apparent disinterest. (examples of avolition include: no longer interested in going out and meeting with friends, no longer interested in activities that the person used to show enthusiasm for, no longer interested in much of anything, sitting in the house for many hours a day doing nothing.)


Catatonia:
People with catatonic type assume peculiar postures and are usually speechless. They may be both rigid and motionless, or they may seem agitated and move around excessively, but always without external stimulus. Catatonic people may also have strange facial expressions, may mimic the behavior of others, and may repeat words that others say. Catatonic behavior is also seen in mood disorders, like bipolar disorder and major depressive disorder, and occasionally in diseases of the central nervous system, like Parkinson's disease.


Delusion od Grandeur:
A delusion in which one believes oneself possessed of great importance, power, wealth, intellect, or ability.


delusion of reference:
Delusions of reference refers to the strongly held belief that random events, objects, behaviors of others, etc. have a particular and unusual significance to oneself.
A person might believe that secret messages about him are broadcast in a weekly television show, to the point where he would record the programs and watch them again and again.


somatic delusion:

a false notion or belief concerning body image or body function. See also delusion.

http://www.enotalone.com/article/3018.html
http://www.mentalhealthchannel.net/schizophrenia/causes.shtml
http://www.schizophrenia.com/diag.php
http://schizophrenia.about.com/od/whatisschizophrenia/f/schiz_symptoms.htm
http://www.answers.com/topic/delusion-1
http://bipolar.about.com/od/glossaryd/g/gl_delusofrefer.htm