Abnormal Psychology

526 CHAPTER 12

Cognitive defi cits can also lead to unusual, although not necessarily disorga-

nized, social behavior. As we’ll discuss in more detail later, people with schizophre-

nia may be socially isolated and avoid contact with others because such interactions

can be overwhelming or confusing. People with schizophrenia can have diffi culty

understanding the usual, unspoken rules of social convention. Also, even after an

episode of schizophrenia has abated, they may not understand when someone is

irritated because they do not notice or correctly interpret the other person’s facial

expression or tone of voice. When irritation erupts into anger, it can seem to come

out of the blue, frightening and overwhelming people with schizophrenia. So, they

may try to tread a safer path and avoid others as much as possible.

The poor social skills and social isolation that are frequently a part of schizo-

phrenia are not included in the DSM-IV-TR criteria, although they are related to

an impaired ability to work (Dickinson, Bellack, & Gold, 2007). The disorganized

behavior, social isolation and poor social skills, and perhaps avolition, all are indi-

cators of underlying cognitive defi cits (Farrow et al., 2005).

Categorical, Not Continual

The DSM-IV-TR definition of schizophrenia (and other disorders; see Chapter 3) is

categorical—that is, someone’s symptoms either meet the criteria (in this case, indicate

that he or she has schizophrenia) or do not. Some researchers in the fi eld question whether

schizophrenia is best described as a category and suggest that instead it should be regarded

as located on a continuum (Tsuang, Stone, & Faraone, 2000;

Westen et al., 2002). Recognizing this limitation, DSM-IV-TR

does provide an alternative way to diagnose schizophrenia,

allowing the clinician to rate the symptoms as absent, mild,

moderate, or severe (American Psychiatric Association, 2000).

Moreover, the list of symptoms is divided into three

dimensions: positive (hallucinations and delusions), disor-

ganized (speech and behavior, and inappropriate affect),

and negative (alogia, avolition, or fl at affect), and each di-

mension is rated separately. These dimensions better refl ect

how the symptoms cluster together: Symptoms within each

of these dimensions tend to vary with each other more than

they do with symptoms on other dimensions. Thus, some-

one with severe hallucinations is more likely to have severe

delusions as well, but not necessarily to have severe nega-

tive symptoms. As shown in Figure 12.1, the alternative

system in DSM-IV-TR enables clinicians and researchers to

note that someone with schizophrenia has differing levels

of symptom severity across each of the three dimensions.

In keeping with current research, this chapter discusses

disorganized symptoms as a separate symptom cluster.

Subtypes of Schizophrenia

DSM-IV-TR specifi es a set of subtypes of schizophrenia, which are based on the pres-

ence or absence of particular positive symptoms. Over time, the diagnosis of subtype

may change, as the prominence of different symptoms shifts (Reichenberg, Reickmann,

& Harvery, 2005). Information on the importance of cognitive defi cits in schizophrenia

has led many researchers to use an alternative set of subtypes. Let’s examine both sets.

DSM-IV-TR Subtypes

DSM-IV-TR identifi es fi ve subtypes of schizophrenia: paranoid, disorganized, cata-

tonic, undifferentiated, and residual.

Paranoid Schizophrenia

Paranoid schizophrenia is characterized by the presence of delusions and auditory

hallucinations that are limited to specifi c topics that have a coherent paranoid or

Figure 12.1

12.1 • Symptoms of Schizophrenia as Positions on

Continuous Dimensions In DSM-IV-TR’s alternative way of

diagnosing schizophrenia, symptoms within the three symptom clusters

are rated on a continuum from absent to severe. Symptoms within each

cluster tend to vary together, but independently of the other clusters.

In the example shown, the individual has severe positive symptoms,

moderate disorganized symptoms, and only mild negative symptoms.

g

Positive symptoms

Absent Mild Moderate Severe

Disorganized symptoms

Absent Mild Moderate Severe

Negative symptoms

Absent Mild Moderate Severe

Paranoid schizophrenia
The subtype of schizophrenia characterized
by the presence of delusions and auditory
hallucinations that are limited to specifi c
topics that have a coherent paranoid or
grandiose theme.