DSM-IV Subtypes of Schizophrenia
In DSM-IV, schizophrenia has been divided into clinical sub-types, based on field trials of the reliability of symptom clusters. The subtypes are divided by the most prominent symptoms, although it is acknowledged that the specific subtype may ex-ist simultaneously with or change over the course of the illness. DSM-IV also initiates an optional dimensional descriptor, which allows the condition to be characterized by the presence or ab-sence of a psychotic, disorganized, or negative symptom dimen-sion over the entire course of the illness.
In DSM-IV, paranoid-type schizophrenia is marked by hallucina-tions or delusions in the presence of a clear sensorium and un-changed cognition. Disorganized speech, disorganized behavior and flat or inappropriate affect are not present to any significant degree. The delusions (usually of a persecutory or grandiose na-ture) and the hallucinations most often revolve around a particu-lar theme or themes. Because of their delusions, these patients may attempt to keep the interviewer at bay, and thus they may appear hostile or angry during an interview. This type of schizo-phrenia may have a later age of onset and a better prognosis than the other subtypes.
Disorganized schizophrenia, historically referred to as hebe-phrenic schizophrenia, presents with the hallmark symptoms of disorganized speech and/or behavior, along with flat or inap-propriate (incongruent) affect. Any delusions or hallucinations, if present, also tend to be disorganized and are not related to a single theme. Furthermore, these patients would not be classified as having catatonic schizophrenia. These patients in general have more severe deficits on neuropsychological tests. According to DSM-IV, these patients tend to have an earlier age at onset, an unremitting course, and a poor prognosis.
Catatonic schizophrenia has unique features that distinguish it from other subtypes of schizophrenia in DSM-IV for Catatonic Schizophrenia. During the acute phase of this illness, patients may demonstrate marked negativism or mutism, profound psychomotor retardation or severe psychomotor agitation, echolalia (repetition of words or phrases in a nonsensical manner), echopraxia (mim-icking the behaviors of others), or bizarreness of voluntary move-ments and mannerisms. Some patients demonstrate a waxy flex-ibility, which is seen when a limb is repositioned on examination and remains in that position as if the patient were made of wax. Patients with catatonic stupor must be protected against bodily harm resulting from the profound psychomotor retardation. They may remain in the same position for weeks at a time. Because of extreme mutism or agitation, patients may not be able to re-port any difficulties. Some patients may experience extreme psy-chomotor agitation, with grimacing and bizarre postures. These patients may require careful monitoring to safeguard them from injury or deterioration in nutritional status or fluid balance.
There is no hallmark symptom of undifferentiated schizophrenia; thus, it is the subtype that meets the criterion A for schizophrenia. but does not fit the profile for paranoid, disorganized, or catatonic schizophrenia.
The diagnosis of residual schizophrenia, according to DSM-IV, is appropriately used when there is a past history of an acute epi-sode of schizophrenia but at the time of presentation the patient does not manifest any of the associated psychotic or positive symptoms. However, there is continued evidence of schizophre-nia manifested in either negative symptoms or low-grade symp-toms of criterion A. These may include odd behavior, some ab-normalities of thought processes, or delusions or hallucinations that exist in a minimal form. This type of schizophrenia has an unpredictable, variable course One must avoid imposing Western definitions of psychosis on nonWestern societies. Psychosis and delusions, by definition, must be beliefs or experiences that are incongruent with those of the patientâ€™s social or cultural background. To determine where culture-bound beliefs end and delusions or inappropriate behav-iors begin in a multicultural world is clearly not possible using only a written algorithm such as DSM-IV. A critical step toward sound cross-cultural clinical care is developing an awareness of and a respect for diversity. Utilizing the expertise of persons fa-miliar with a specific culture allows appropriate diagnosis and treatment of schizophrenia worldwide