PSYC62: Chapter 15 Schizophrenia Schizophrenia is a severe, lifelong mental illness consisting of disturbed thought processes and poor emotional responsiveness. The symptoms of schizophrenia consist of either positive symptoms or negative symptoms. Positive symptoms are the addition of abnormal behaviours such as hallucinations, delusions, and thoughts of persecution to diagnosis of schizophrenia. Negative symptoms are a reduction of normal behaviours such as emotional responsiveness, social withdrawal, reduced movement and lack of motivation. There are five types of schizophrenia: (1) a paranoid type characterized by prominent positive symptoms (2) a catatonic type characterized by predominantly negative symptoms, including immobility. (3) a disorganized type characterized by disorganized behaviours and silly or immature emotional expression (4) an undifferentiated type that does not appropriately fit these other categories (5) a residual type for patients who now exhibit less prominent symptoms of schizophrenia but did so in the past. Studies show the 5070 of individuals with schizophrenia exhibit chronic symptoms while the remaining 3050 tend to exhibit residual features. About 13 of people are treatment resistant patients Treatment resistant patients exhibit minimal or no improvements after two trials with either typical or atypical antipsychotic drugs. Nearly all individuals with schizophrenia have moderate to severe deficits in cognitive functioning, including working memory, reference memory, attention and executive functioning compared to the general population. Many patients with schizophrenia demonstrate a sensorygating deficit that is characterized by a diminished capacity to filter out unimportant stimuli in their environment. This may lead to misperceptions of their environment, possibly facilitating delusional behaviours. Researchers assess sensorygating deficits by using a prepulse inhibition procedure. The prepulse inhibition procedure consists of determining ones ability to demonstrate a weaker reflexive response to a sudden stimulus after exposure to a weaker form of the stimulus immediately before. The MATRICS program seeks to identify cognitive features of schizophrenia and determine the best treatment strategies for reducing these impairments. Diagnosis of schizophrenia is usually found in ones late teens or early 20s.