Performance of nonpsychotic relatives of schizophrenic patients on cognitive tests. Psychiatry Res
ABSTRACT We tested 54 nonpsychotic first degree relatives of 23 schizophrenic probands and 18 control subjects matched for age and education on several neuropsychological tests. The tests were selected to assess overall intellectual ability or because previous work indicated that they are particularly sensitive measures of cognitive dysfunction in schizophrenic patients. The relatives of schizophrenic patients performed significantly worse than the control subjects on tests of verbal fluency and on Trailmaking, part B. Each of these tests contributed unique variance to the discrimination between groups. The groups did not differ significantly on the number of perserverative errors on the Wisconsin Card Sorting Test, Wechsler Adult Intelligence Scale-Revised block design or vocabulary, or Trailmaking, part A. Eight relatives who met DSM-III-R criteria for schizotypal personality disorder were more impaired than the remaining 46 relatives on letter fluency, but otherwise their performance was similar to that of nonschizotypal relatives. These data suggest that close relatives of schizophrenic patients may have subtle neuropsychological impairments that are not necessarily associated with clinical symptoms of schizophrenia spectrum disorders.
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- "They predict poorer medication (Burton, 2005) and treatment (Prouteau et al, 2004) adherence, reduced adaptive and social skills (Bowie and Harvey, 2005), dysfunctional personality traits (Gurrera et al, 2005), and increased risk of relapse in first-episode patients (Chen et al, 2005). The cognitive dysfunction of schizophrenia appears to involve almost all the known neurotransmitter systems (Tamminga, 2006) and is also be found in probands' non-schizophrenic relatives (Keefe et al, 1994; Sitskoorn et al, 2004). "
ABSTRACT: Cognitive deficits observed in schizophrenia are also frequently found in individuals with other schizophrenia spectrum disorders, such as schizotypal personality disorder (SPD). Dopamine appears to be a particularly important modulator of cognitive processes such as those impaired in schizophrenia spectrum disorders. In a double-blind, placebo-controlled clinical trial, we administered pergolide, a dopamine agonist targeting D(1) and D(2) receptors, to 25 participants with SPD and assessed the effect of pergolide treatment, as compared with placebo, on neuropsychological performance. We found that the pergolide group showed improvements in visual-spatial working memory, executive functioning, and verbal learning and memory. These results suggest that dopamine agonists may provide benefit for the cognitive abnormalities of schizophrenia spectrum disorders.Neuropsychopharmacology: official publication of the American College of Neuropsychopharmacology 05/2010; 35(6):1356-62. DOI:10.1038/npp.2010.5 · 7.83 Impact Factor
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- "However, previous studies using this strategy are limited by the cross-sectional nature of assessments (Keefe et al., 1994b) and inclusion of second degree relatives, which may dilute the genetic loading for schizophrenia (Whyte et al., 2006). "
ABSTRACT: Genetic diathesis to schizophrenia may involve alterations of adolescent neurodevelopment manifesting as cognitive deficits. Brain regions mediating executive function (fronto-striatal circuits) develop during adolescence while those supporting elementary aspects of attention (e.g. sustained focused attention) have a more protracted maturation beginning in childhood. We hence predicted that adolescents at risk for schizophrenia would show a failure of normal maturation of executive function. We prospectively assessed 18 offspring and 6 siblings of schizophrenia patients (HR) and 28 healthy controls at baseline, year-1 and year-2 follow-up using the Continuous Performance Test [visual-d'] and Wisconsin Card Sort Test (WCST). Perseverative errors on the WCST in HR remained stable but decreased in controls over the follow-up (study-group by assessment-time interaction, p=0.01, controlling for IQ). No significant study-group by assessment-time interactions were seen for sustained attentional performance. HR may not improve while healthy subjects progressively improve on executive function during adolescence and early adulthood. Our results suggest an altered maturational trajectory of executive function during adolescence in individuals at familial risk for schizophrenia.Progress in Neuro-Psychopharmacology and Biological Psychiatry 04/2010; 34(3):469-74. DOI:10.1016/j.pnpbp.2010.01.015 · 4.03 Impact Factor
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- "A recent meta-analysis revealed a large effect size (0.68) in category fl uency (Snitz et al., 2006). Verbal fl uency may be signifi cantly correlated with intelligence (Gilvarry et al., 2001); another study reported defi cits in verbal fl uency and executive function among relatives of SZ patients (Keefe et al., 1994). The possibility of verbal fl uency defi cits in young relatives was assessed by the Pittsburgh High-Risk Study (see below) which found signifi cant defi cits at the baseline assessment. "
ABSTRACT: Neurocognitive deficits in schizophrenia (SZ) are thought to be stable trait markers that predate the illness and manifest in relatives of patients. Adolescence is the age of maximum vulnerability to the onset of SZ and may be an opportune "window" to observe neurocognitive impairments close to but prior to the onset of psychosis. We reviewed the extant studies assessing neurocognitive deficits in young relatives at high risk (HR) for SZ and their relation to brain structural alterations. We also provide some additional data pertaining to the relation of these deficits to psychopathology and brain structural alterations from the Pittsburgh Risk Evaluation Program (PREP). Cognitive deficits are noted in the HR population, which are more severe in first-degree relatives compared to second-degree relatives and primarily involve psychomotor speed, memory, attention, reasoning, and social-cognition. Reduced general intelligence is also noted, although its relationship to these specific domains is underexplored. Premorbid cognitive deficits may be related to brain structural and functional abnormalities, underlining the neurobiological basis of this illness. Cognitive impairments might predict later emergence of psychopathology in at-risk subjects and may be targets of early remediation and preventive strategies. Although evidence for neurocognitive deficits in young relatives abounds, further studies on their structural underpinnings and on their candidate status as endophenotypes are needed.Frontiers in Human Neuroscience 03/2010; 3:62. DOI:10.3389/neuro.09.062.2009 · 2.90 Impact Factor