Cognitive and behavioral precursors of schizophrenia

Abstract

Attentional deficits are well-established characteristics of patients with schizophrenia and their at-risk offspring, suggesting a biological connection between attention and schizophrenia. The goal of this study is to clarify the developmental role of attention in the illness. Data has been collected from 87 subjects at high and low risk for schizophrenia who have participated in the New York High-Risk Project from 1977 to the present. Individuals are considered to be at high risk if either or both of their parents has schizophrenia. Analyses of attention and global behaviors, measured at intervals from about 12 to 26 years of age, indicate (a) attentional deficits can be reliably detected in high-risk children who will develop future schizophrenia-spectrum disorders (the prespectrum [PSP] group); (b) these deficits are stable, enduring over time, and appear to reflect a compromised attentional capacity; (c) attention is not affected by the onset of illness in the PSP group; (d) for all subjects, attention and global behaviors follow independent developmental pathways; and (e) behavioral difficulties, but not attention deficits, appear to be highly sensitive to environmental factors, especially rearing by a mentally ill parent. It is concluded that in PSP individuals impaired attention probably results from prenatal developmental abnormalities (possibly on the cellular level) and is likely to be a marker of a biological vulnerability to schizophrenia. In addition, attentional deficits, as opposed to early behavioral difficulties, are concluded to be a useful first step in screening for youngsters in need of early intervention.

Advances in endophenotyping schizophrenia

“…Effect sizes for discrimination of schizophrenia patients from controls range from 0.45 to 3.30 (2). A longitudinal study of children of schizophrenia patients has found that those who later developed schizophrenia spectrum disorders had shown CPT deficits at age 12-13 (61). Positron emission tomography (PET) activation studies with the degraded stimulus CPT support the role of cortical-striato-thalamic pathways in the deficits observed in schizophrenia (62).…”

The Cognitive Neuroscience of Working Memory: Relevance to CNTRICS and Schizophrenia

“…Further, a large body of work has demonstrated that individuals with schizophrenia have deficits on a varied set of working memory tasks [e.g., 2,3] that are associated with impairments in a range of neural mechanisms [4]. There is some data to suggest that the degree of impairment in certain aspects of working memory predicts later onset of schizophrenia [5,6]. In addition, the level of working memory impairment predicts the degree of social and occupational impairment in individuals with schizophrenia [e.g., 7,8].…”

Source monitoring for actions in adolescents with 22q11.2 deletion syndrome (22q11DS)

“…Cognitive development in this syndrome may include learning difficulties (Swillen et al 1999), speech and language difficulties (Moss et al 1999 ;Glaser et al 2002), and below-average IQ (Golding-Kushner et al 1985 ;Swillen et al 1997). Verbal and executive deficits in youngsters with the deletion resemble those of other groups that at high risk for schizophrenia (Cornblatt et al 1999). Two studies suggest that a decrease in verbal IQ accompanies the onset of positive symptoms in adolescents with 22q11DS (Gothelf et al 2005 ;Debbané et al 2006a), and one study suggests that executive function deficits in affected children and adolescents could reflect genetic risk for schizophrenia (Lewandowski et al 2006).…”