Many individuals with schizophrenia will experience remission of their

Many individuals with schizophrenia will experience remission of their positive symptoms, but may not function within normal societal expectations. It is well recognized that these individuals with schizophrenia may continue to experience persistent negative symptoms (Buchanan, 2007; Pogue-Geile & Harrow, 1985). Although the importance of these residual negative symptoms in limiting functional recovery is being recognized, and treatments have been developed to target these symptoms, there is little research examining the role of residual depressive symptoms in schizophrenia. Our results suggest that for individuals who are in remission from positive symptoms, depressive symptoms have the potential to impair functional recovery in a similar way as negative symptoms. Furthermore, residual depressive symptoms were found to be independent of residual negative symptoms, indicating that although they are distinct constructs, as measured in the current study, both are equally important to consider as persistent symptoms that require treatment.
This study has several limitations that should be taken into consideration, some of which may limit the generalizability of these findings to other samples. This study features the performance of older patients with a long-term course of illness and may not generalize to performance of younger or more acutely ill individuals. The criteria used to classify individuals into positive and negative symptoms groups were based on the PANSS – a semi-structured interview, whereas the criterion for the presence of depressive symptoms was based on the BDI – a self-report questionnaire. Self-report questionnaires can suffer from validity issues and using a self-report measure of depression may have decreased the validity of the depressive symptom measurement compared to the negative and positive symptom measurements. Our sample size per group was relatively small, potentially leaving us underpowered to detect significant correlations within some groups. However, we used moderation analyses to examine differences in relationships between groups, increasing our power to detect these effects. We also acknowledge that the SLOF does not contain identical items to the UPSA or SSPA, and therefore some of the discrepancy observed may be the result of differences in content, however, it actin inhibitor is unlikely that item differences can fully account for the varying relationships found among the symptom classifications. Lastly, although real-world observation may be the ideal way to measure functioning, this method still relies on third-party reports which may not be accurate representations of behavior across diverse situations (Pyne et al., 2003), might not be available to all persons, and can be confounded if the participant knows they are being observed (Robson, 2002).

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Impaired neurocognitive function is one of the core features of schizophrenia spectrum disorders (Green et al., 2004). Assessment and treatment of cognitive deficits in schizophrenia requires the employment of comprehensive, standardized test batteries describing cognitive function across several domains. One such battery is the Measurement and Treatment Research to Improve Cognition in Schizophrenia [MATRICS] Consensus Cognitive Battery (MCCB), using ten tests to assess seven neurocognitive domains (Nuechterlein & Green, 2006). It is often referred to as the gold standard for neuropsychological assessment in schizophrenia, but has also been employed in other conditions of psychopathology, e.g., bipolar disorder (Burdick et al., 2011).
In addition to the United States norms for the healthy 20-59 age group (Nuechterlein & Green, 2006), Spanish (Rodriguez-Jimenez et al., 2012), Norwegian (Mohn et al., 2012), Japanese (Kaneda et al., 2013) and Singaporean (Rapisarda et al., 2013) reference data have been published for the MCCB.
General intellectual function and neuropsychological test performance are related, but are separate constructs, as the degree of neuropsychological test variance explained by IQ is significant, but not complete (Ackerman et al., 2005; Ardila, 1999; Diaz-Asper et al., 2004). The associations of IQ scores to the scores of most of the MCCB subtests have been reported. However, sticky ends is important to establish how IQ is related to performance on the MCCB as a whole, in the same individuals, and in large samples across relevant demographic variables. Moreover, many clinical neuropscyhologists routinely add IQ tests to their assessment of general cognitive function. However, a prolonged and fatiguing test session should be avoided if necessary, and IQ testing on top of a comprehensive neurocognitive function assessment could be redundant if the relationship between IQ scores and other measures of cognitive function is strong.