Impaired Context Processing is Attributable to Global Neuropsychological Impairment in Schizophrenia and Psychotic Bipolar Disorder

Abstract

Background: Context processing may reflect a specific cognitive impairment in schizophrenia. Whether impaired context processing is observed across psychotic disorders or among relatives of affected individuals, and whether it is a deficit that is independent from the generalized neuropsychological deficits seen in psychotic disorders, are less established. Methods: Schizophrenia, schizoaffective, and psychotic bipolar probands (n = 660), their first-degree relatives (n = 741), and healthy individuals (n = 308) studied by the Bipolar-Schizophrenia Network on Intermediate Phenotypes consortium performed an expectancy task requiring use of contextual information to overcome a prepotent response. Sensitivity for target detection and false alarm rates on trials requiring inhibition or goal maintenance were measured. Results: Proband groups and relatives with psychosis spectrum personality traits demonstrated reduced target sensitivity and elevated false alarm rates. False alarm rate was higher under inhibition vs goal maintenance conditions although this difference was attenuated in schizophrenia and schizoaffective proband groups. After accounting for global neuropsychological impairment, as reflected by the composite score from the Brief Assessment of Cognition in Schizophrenia neuropsychological battery, deficits in schizophrenia and bipolar proband groups were no longer significant. Performance measures were moderately familial. Conclusion: Reduced target detection, but not a specific deficit in context processing, is observed across psychotic disorders. Impairments in both goal maintenance and response inhibition appear to contribute comparably to deficits in schizophrenia and schizoaffective disorder, whereas greater difficulty with response inhibition underlies deficits in bipolar disorder. Yet, these deficits are not independent from the generalized neurocognitive impairment observed in schizophrenia and psychotic bipolar disorder.

Levels of Cognitive Control: A Functional Magnetic Resonance Imaging-Based Test of an RDoC Domain Across Bipolar Disorder and Schizophrenia

“…Significant or trend-level associations were observed between poverty and disorganization symptoms and poor task performance across BPD and SZ patient groups, suggesting these relationships may transcend diagnostic categories. Importantly, these findings enrich those from previous behavioral AX-CPT studies (Brambilla et al, 2007;Reilly et al, 2017) by suggesting that the previously reported intermediate deficits in BPD (relative to SZ and healthy subjects) are also associated with reductions in frontoparietal activation.…”

“…Specifically, we hypothesize (1) the presence of impaired goal maintenance of CC in patients (vs controls), and (2) while SZ and BPD would show the same pattern of cognitive and functional neural circuitry deficits, this effect would vary in severity across the recent onset groups, with a significant linear trend reflecting CC in BPD that lies between controls and SZ patients. This pattern would be consistent with previous AX-CPT behavioral results (Brambilla et al, 2007) cognitive meta-analyses (Bora and Pantelis, 2015;Reichenberg and Harvey, 2007;Robinson et al, 2006), and several findings from the Bipolar-Schizophrenia Network on Intermediate Phenotypes (B-SNIP) consortium (Hill et al, 2013;Ivleva et al, 2016;Reilly et al, 2017;Sheffield et al, 2017). As we were interested in common phenomenological endpoints (eg, psychosis, possibly suggestive of shared etiologies) we restricted our analysis to BPD Type I patients (who presented with psychotic features).…”

“…Nonetheless, as abnormal CC processes are known to contribute to cognitive deficits across a range of domains (Lesh et al, 2011;Niendam et al, 2012), it is likely that the results observed in the B-SNIP study may be driven by the CC deficits reported here. Related to this point, another B-SNIP report found that generalized cognitive deficits accounted for reduced goal maintenance in BPD and SZ during the DPX (Reilly et al, 2017), although the reverse relationship (the influence of goal maintenance on general cognition) was not examined.…”

“…In regard to BPD, a previous AX-CPT behavioral study reported that BPD patients performed (AX errors) intermediately between controls and SZ patients, suggestive of a continuum of deficits across disorders (Brambilla et al, 2007). A more recent behavioral study in a much larger sample using the dot probe expectancy task (DPX; an AX-CPT variant) found the same pattern of CC deficits driven by significant differences between HC, BPD, and SZ groups (Reilly et al, 2017).…”

Cognitive Deficits in Psychotic Disorders: A Lifespan Perspective

“…For instance, in a task of context processing, psychotic bipolar patients demonstrated reduced target sensitivity and increase false alarms, largely due to impaired response inhibition (Reilly et al 2017), which was specific to bipolar patients compared to schizophrenia or schizoaffective disorder. In an executive function task of set-shifting, psychotic bipolar disorder patients had increased rates of regressing to a previously established response (i.e., regressive errors) (Hill et al 2015).…”