The purpose of this review was to examine the relationship between social cognition (SP, EP, ToM, and AS) and functional outcome (social behavior in the milieu, community functioning, social skill, and social problem solving). Based on this review, we have drawn the following conclusions: First, there is a fairly consistent relationship between SP and various domains of functional outcome, particularly social problem solving, social behavior in the milieu, and community functioning. There is promising, but still inconsistent, evidence for a relationship between SP and social skill. Finally, there is growing evidence that SP may serve as a mediator between neurocognition and functional outcome. Second, EP appears to have a fairly consistent, yet modest, relationship with community functioning, social skill, and social behavior in the milieu, while no study has examined its relationship with social problem solving. Finally, one study suggests that EP may mediate the relationship between neurocognition and functional outcome.
Third, the domains of ToM and AS have received far less attention in terms of their functional significance. Current work is suggestive of a significant association between ToM and social skills and possibly with community functioning and social behavior in the milieu, but clearly more research is needed to draw firm conclusions. Only 2 studies have examined the relationship between attributions and functional outcome. This is likely due to the fact that AS has typically been studied in the context of persecutory delusions, rather than functional outcome. However, findings suggest that attributions might be related to functional outcome, particularly those in which the behaviors match the content of the attributional biases (eg, hostile attributional biases and aggressive behavior).52
These conclusions, however, should be met with caution due to the early and still developing nature of the literature. As more data become available on the relationship between social cognition and functional outcome, and some of the methodological problems plaguing this area are addressed in future studies, the findings from the current review may or may not change.
This review raises a number of issues that need to be considered in future research. At the conceptual level, a critical question is which aspects of functional outcome are expected to change to relate to specific domains of social cognition. In the extant literature, many studies focus on the notion that there should be a relationship between social cognition and functional outcome, but these relationships are generically defined, and do not specify which domain of social cognition should relate to which domain of functional outcome. In essence, the field needs to move from exploratory-based studies to hypothesis-based ones. For example, one might expect social cognition to be more strongly related to laboratory-based direct assessments of particular skills, rather than to community functioning. In fact, performance-based assessments might provide the most theoretically relevant link to neurocognition and social cognition in that they assess whether individuals are capable of performing certain behaviors in specific situations.78
Of course, these skills are influenced by factors such as the motivation of the individual, but arguably, they provide a closer approximation of an individual's competence in particular areas than other measures of functional outcome. Broader-based domains of functional outcome (eg, recreational and work functioning) are not always strongly related to performance-based assessments,70,79,80
and in addition, they may be influenced by factors outside the individual's control, such as level of social support, financial means, personal resources (eg, having an automobile), etc.38
A related conceptual issue is how social cognition relates to functional outcome. The majority of studies in this review examined social cognition and functional outcome at a single time point, thus assuming that they covary with one another, but with little consideration for causal relationships. In addition, as noted above, 2 longitudinal studies found evidence that EP was predictive of functional outcome at a later time point.38,39
These findings provide preliminary support for a causal relationship between social cognition and functional outcome, but clearly more long-term studies are needed.
The review also raises a number of critical methodological issues. First, it is essential for future studies to use well-defined measures of functional outcome and multiple measures of social cognition to help elucidate the relationships between these constructs. Currently, it is difficult to examine specific relationships or employ meta-analytic techniques, given the different measures utilized across studies. Of course, the National Institute of Mental Healths' Measurement and Treatment Research to Improve Cognition in Schizophrenia program (MATRICS)81,82
is an important step in this direction because well-defined measures of neurocognition have been chosen to comprise this battery (and a number of social functioning tasks are included under secondary outcomes). However, only a single social cognitive measure is included in the MATRICs battery (the Mayer-Salovey-Caruso Emotional Intelligence Test),83
and it does not address the range of social cognitive abilities impaired in schizophrenia. Second, it is important for future studies to clearly operationally define the constructs of interest as well as to utilize measures with sound psychometric properties. For example, we noted that basic psychometric information for ToM measures, such as reliability and validity, are often not presented and, when they are, their coefficients are not satisfactory,68
a problem that also has been observed for measures of EP.72
Third, sample characteristics, such as years of education achieved, duration of illness, and medication dosages, were inconsistently reported. Relatedly, over half of the reviewed studies had samples with over 70% of the participants being male. Given that schizophrenia occurs fairly often in females and that females with schizophrenia may have different illness trajectories and perhaps better social functioning, treatment response, and neuropsychological abilities than males,84–86
it is critical for future work to attempt to recruit women with schizophrenia more heavily.
Fourth, over half of the research in this area included only inpatients. Although improving functioning in treatment settings (ie, social behavior in the milieu) is a valuable treatment goal, increasing current understanding of outpatient community functioning may be more pressing, given the move toward community-based care and that the largest subgroup of individuals with schizophrenia are outpatients.87
And finally, most studies were underpowered. Specifically, 65% of studies had power estimates of .50 or less for detecting a moderate effect size, whereas only 17% of studies had adequate power of .80. Thus, extant research in this area may be underestimating significant findings due to the majority of the studies suffering from low statistical power.
Despite these limitations, it is clear that significant relationships exist between the domains of social cognition and functional outcome. Given the preliminary evidence that social cognition does have functional significance in schizophrenia, there has been growing interest in devising interventions aimed at improving functional outcomes via remediation of social cognitive deficits. The rationale for this endeavor is further strengthened by the fact that prominent current interventions, such as symptom-focused cognitive behavior therapy (CBT), show limited generalizability to improvements in social functioning.88–90
The social cognitive interventions that have been developed to date can be classified as either “targeted” or “broad based.” Targeted interventions focus on a specific social cognitive domain (eg, EP), whereas broad-based interventions combine a variety of psychosocial approaches, including cognitive remediation, social skills training, and social cognitive skill building. Several targeted interventions have been shown to improve EP in schizophrenia.91–96
Similarly, broad-based interventions have been found to improve some of the cognitive and social cognitive skills that they have targeted.97–102
These findings are promising but also highlight several key issues that remain unaddressed. First, can we expect the narrow focus of targeted interventions to yield improvements across social cognitive domains or to generalize to social functioning? Second, if targeted interventions are too narrow, are broad-based interventions too burdensome? That is, is it necessary to stack social cognitive training atop intensive cognitive remediation and social skills training or might social cognitive training alone be sufficient to improve social functioning?
In an effort to address these issues, our research group has recently developed a social cognitive intervention that targets the 3 major domains that are impaired in schizophrenia: EP, ToM, and AS. Social Cognition and Interaction Training (SCIT) is an empirically derived, multimodal, 24-week group intervention for individuals with schizophrenia. Preliminary results from SCIT are promising. In our first (uncontrolled) pilot study, we showed that SCIT was associated with improvements in ToM, AS, and symptoms and that social cognitive and symptom improvement was independent of one another.103
In a second pilot study, an initial group of participants who received SCIT showed improvement in all 3 social cognitive domains (EP, ToM, and attributions) as well as social functioning (as measured by the Social Functioning Scale104
and aggression on the ward (as measured by incident reports) and showed a reduced need for closure and better tolerance for ambiguity (D. R. Combs, S. D. Adams, D. L. Penn, D. L. Roberts, J. Tiegreen, P. Stem, unpublished data, 2006) (as measured by the Need for Closure Scale).105
All effect sizes were in the medium to large range. Although promising, these preliminary, open-trial results require replication in a controlled study before confident conclusions can be drawn.
At the current juncture, it is unclear how successful these social cognitive interventions will be; similar attempts in the cognitive remediation literature have been met with only modest success in improving neurocognitive abilities106
or in impacting functional outcome.107
However, it is hoped that over time, these interventions will play a prominent role—alongside medication management, CBT, social skills training, and cognitive remedation—in addressing the perennial riddle of improving functional outcome in schizophrenia.