Longitudinal studies of antisaccades in antipsychotic-naive first-episode schizophrenia

Center for Cognitive Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA.
Psychological Medicine (Impact Factor: 5.94). 05/2006; 36(4):485-94. DOI: 10.1017/S0033291705006756
Source: PubMed


Prefrontal cortical dysfunctions, including disturbances in adaptive context-specific behavior, have been reported in neuropsychological and brain imaging studies of schizophrenia. Some data suggest that treatment with antipsychotic medications may ameliorate these deficits.
We investigated antisaccade performance in 39 antipsychotic-naive, first-episode schizophrenia patients who were re-evaluated 6 weeks after treatment initiation. A group of matched healthy subjects were examined at similar time-points. Patients and healthy individuals available for longer-term testing were re-assessed 26 and 52 weeks after initial testing.
Before treatment, patients showed elevated rates of response suppression errors and prolonged latencies of correct antisaccades. Increased rates of antisaccade errors were associated with faster response latencies during a separate, visually guided saccade task, but only prior to treatment. Throughout the 1-year follow-up, patients progressively improved in their ability to voluntarily suppress context-inappropriate behavior. Although treatment assignment was by clinician choice, results of exploratory analyses revealed that patients treated with risperidone progressively planned and initiated correct antisaccades more quickly than patients receiving haloperidol.
Deficits in the voluntary control of spatial attention are exaggerated during acute episodes of illness, but remain an enduring aspect of prefrontal dysfunction in schizophrenia even after treatment. During acute illness, speeded sensorimotor transformations may compound these deficits and contribute to the heightened distractibility associated with acute psychosis. Continued improvement in task performance throughout the 1-year follow-up suggests that partial normalization of prefrontal cognitive functions resulting from antipsychotic treatment may have a longer and more gradual time course than the reduction of acute psychotic symptoms.

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Available from: John A Sweeney, Jan 15, 2015
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    • "Arguing against the possibility that antipsychotic medications are giving rise to altered SSRT in patient groups is the absence of a significant relationship between standardized antipsychotic dose and countermanding performance measures and absence of a difference in countermanding performance measures between bipolar patients that were and were not receiving antipsychotic treatment. Additionally, atypical antipsychotic medication has been found to improve inhibitory performance, as measured with the antisaccade task (Harris et al., 2006). Further, based on studies in which healthy subjects are administered antipsychotic medication, it is unlikely that medication effects are giving rise to longer post-canceled slowing in patients with SZ relative to HC and BP. "
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    • "Because acute illness may disrupt inhibitory control in bipolar disorder (Strakowski et al., 2010) and schizophrenia (Harris et al., 2006; Hill et al., 2009), patients were clinically stable and on consistent psychopharmacological treatment for at least one month. Symptom severity and functioning were rated using the Positive and Negative Symptom Scale (Lancon et al., 2000), Young Mania Rating Scale (Young et al., 2000), Montgomery–Asberg Depression Rating Scale (Montgomery and Asberg, 1979), Birchwood Social Functioning Scale (Birchwood et al., 1990), Schizo-bipolar Scale (Keshavan et al., 2011) and Barratt Impulsiveness Scale 11 (Patton et al., 1995). "
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    • "In a large, multi-center pharmacological study of SPQ schizotypy it was observed that the D2/D3 receptor antagonist amisulpride improved working memory and verbal fluency performance in persons with high levels of schizotypy but worsened it in medium schizotypal controls (181). Data from the same study showed that administration of 7 mg risperidone led to deterioration in antisaccade task performance in medium schizotypy controls, whereas in high schizotypy a non-significant tendency toward improvement was observed (182), compatible with the improvements in antisaccade performance seen in schizophrenia with risperidone treatment (183, 184). Together, these data suggest that persons with high schizotypy benefit from antipsychotic compounds similar to patients with schizophrenia, or at least tolerate them, whereas controls do not. "
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