With the new focus on functional recovery in schizophrenia, factors limiting function in schizophrenia are receiving increasing attention.
Neurocognitive (NC) impairment accounts for 20-60% of the variance in real-world outcome. The effect sizes of the associations between NC and functional outcome tend to be medium for specific domains and larger for summary scores. Mapping NC deficits often requires the use of extensive test batteries that are lengthy and costly and require advanced training in assessment to score and utilize the results. The currently available NC assessment instruments differ widely in the population intended for use, administration time, interpretation of results, and the assessment of certain NC domains.
Social cognition (SC) contributes to functional outcomes beyond the influence of NC and may have a greater impact than NC on social outcomes. In addition, SC may mediate the relationship between NC and social functions in both chronic and first-episode patients. The degree of the relationship between SC and functioning varies, depending on the SC domain and the type of functional outcome assessed. In the past, there has been controversy over what SC processes should cover. Moreover, the most critical issue is that there is no consensus in the field as to which measures best assess each SC domain. As a result, a heterogeneous group of tasks have been administered with significant conceptual overlap and questionable psychometric properties across studies. This problem is present across all SC domains and contributes to the inconsistency of the reported findings.
The assessment of real-life functioning in schizophrenia presents complex challenges from variability in the operational definition of functional outcome to problems in identifying optimum information sources. In this context, there are still few satisfactorily reliable instruments for the assessment of functional outcomes that are practical in terms of time involved, and most real-life functional outcome scales seem to be largely redundant with each other when utilized simultaneously.
This update describes the main NC and social cognition (SC) batteries and real-world assessments used in schizophrenia and discuss their advantages and disadvantages.