The Effect of Cognitive Remediation Training on Functional Connectivity and Social Cognition in Schizophrenia

In addition to a combination of positive and negative symptoms, persons suffering with schizophrenia also experience cognitive symptoms such as impaired executive function, attention, and learning and memory. Cognitive remediation training was previously shown to benefit individuals diagnosed with schizophrenia in terms of cognitive performance, as well as with regard to functional outcomes.

Investigators affiliated with University of Pittsburgh and Harvard Medical School recently reported that psychosocial cognitive remediation appears to have a beneficial effect on functional brain connectivity at rest in patients who are in the early course of schizophrenia. Their findings were published in Journal of the Society for Social Work and Research.

The researchers recruited individuals in the early course of schizophrenia or schizoaffective disorder into the 2-year long randomized controlled trial to assess the impact of cognitive enhancement intervention (n=25) or enriched supportive therapy (n=16) on pseudo resting-state functional brain connectivity. Cognitive enhancement therapy involved 60 hours of computer-based neurocognitive training, as well as 45 structure 1.5-hour long social-cognitive groups. Enriched supportive therapy, on other hand, is an individual-based support approach, and, in this trial, it served as an active comparison treatment.

Also, investigators evaluated social cognition and emotion processing by using the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) to assess whether cognitive remediation had a positive impact on measures of cognitive performance. The participants in the two groups did not differ significantly in terms of age, sex, race/ethnicity, educational attainment, illness duration, IQ, or antipsychotic medication dose. Less than 70% (n=17) and 50% (n=8) of participants in the cognitive enhancement therapy or the enriched supportive therapy, respectively, completed the fMRI procedure at the second follow-up, which was 2 years after the start of this trial.

Findings indicate that participants in the enriched supportive therapy group presented with a decrease in functional brain connectivity over time (d=-1.16, df=14, n=16, P=.015), whereas the participants in the cognitive enhancement therapy group showed a non-significant increase in connectivity over time between the posterior cingulate and left dorsolateral prefrontal cortex (d=.33, df=35, n=25, P=.233). Researchers reported a similar pattern in functional connectivity between the posterior cingulate and the insula, but the observed increase in connectivity among the participants in the cognitive enhancement therapy was significant between time points (d=.81, df=35, n=25, P=.005). Again, the participants in the enriched supportive therapy group presented with a significant reduction in functional connectivity between the posterior cingulate and the insula (d=-1.16, df=14, n=16, P=.015).

Data also show that the participants in the cognitive enhancement therapy group presented with improved emotion perception, but not improved emotion facilitation or emotion understanding. “Increased posterior cingulate-right insula connectivity significantly mediated the previously observed beneficial differential effect of cognitive enhancement therapy on emotion perception….and, increased functional connectivity with the left dorsolateral prefrontal cortex also significantly mediated the effect of cognitive enhancement therapy on emotion regulation,” the authors wrote in their publication.

Thus, it appears that cognitive enhancement therapy may be protective in terms of “functional disconnectivity between frontal and temporal brain networks in early course schizophrenia.” Also, the observed changes in functional connectivity may therefore “serve as active mechanisms for social-cognitive enhancement.”

Reference

Eack SM, Newhill CE, Keshavan MS. Cognitive enhancement therapy improves resting-state functional connectivity in early course schizophrenia. J Soc Social Work Res. 2016;7:211-230.