Impaired Attention, Genetics, and the Pathophysiology of Schizophrenia

Abstract

Impaired attention is commonly observed among schizophrenia patients and those at genetic risk for the disease. This article reviews over 40 studies that used various versions of the Continuous Performance Test (CPT) as the primary measure of attention. These studies of normal subjects, affected patients, and various at-risk populations demonstrate that the CPT is a psychometrically sound procedure that consistently discriminates affected patients from controls. Sufficiently difficult versions of this task have also demonstrated that impaired attention is (1) evident in schizophrenia patients regardless of clinical state, (2) detectable before illness onset, (3) apparently heritable, (4) specific--in terms of distinct profile patterns--to schizophrenia, and (5) predictive of later behavioral disturbances in susceptible individuals. Selected studies are also discussed that examine the role of attentional deficit in the pathophysiology of schizophrenia and its potential consequences for personality development. With respect to pathophysiology, preliminary data suggest that subcortical brain dysfunction has an important role in the attentional deficits tapped by the CPT. With respect to personality, an association between chronically impaired attention and deficient social skills has been found. It is concluded that the CPT is a cost-effective measure of the attentional deficit commonly found in affected schizophrenia subjects and those at risk for the disorder, and is therefore a potentially valuable screening device for preventive intervention programs.

Effects of Atypical Neuroleptics on Sustained Attention Deficits in Schizophrenia A Trial of Risperidone Versus Haloperidol

“…Similar deficits on CPT performance have also been demonstrated in populations at increased risk for schizophrenia, such as those with schizotypal personality disorders , relatives of schizophrenic patients (Chen et al 1998b;Mirsky et al 1995;Rutschmann et al 1977), and nonclinical subjects with high schizotypy scores (Chen et al 1998a;Lenzenweger et al 1991). All these characteristics indicate that CPT performance deficits are potential endophenotypic indicators (i.e., behavioral characteristics that mark the presence of genotypic risk) of schizophrenia (Cornblatt and Keilp 1994).…”

More evidence supports the association of PPP3CC with schizophrenia

“…Sustained attention deficits as measured on the continuous performance test (CPT) 13 have been shown to be presented not only in schizophrenic patients but also in subjects with schizotypal personality disorder and in nonpsychotic relatives of schizophrenic patients. [14][15][16][17][18][19] The normalized z score for d 0 , which is the sensitivity measure of sustained attention assessed by CPT, has been frequently used as a schizophrenia endophenotype. When patients with schizophrenia having a z score below À2.5 were assigned to have deficit in sustained attention, the recurrence risk ratio for schizophrenia among parents or siblings in the subgroup of schizophrenia with this CPT endophenotype was higher than that in the whole group of schizophrenia probands.…”

Reversal of Clozapine Effects on Working Memory in Rats with Fimbria–Fornix Lesions

“…Cognitive impairment in schizophrenia is pronounced and includes deficits in attention and memory function (Cornblatt and Keilp, 1994;Gallhofer et al, 1996;Sharma and Mockler, 1998;Stip, 1996;Tollefson, 1996). Such impairments appear to be a core feature of schizophrenia (Weinberger and Gallhofer, 1997), but are exacerbated by classic antipsychotic drugs (Gallhofer et al, 1996;Levin et al, 1996;Stip, 1996).…”