Elsevier

Biological Psychiatry

Volume 73, Issue 10, 15 May 2013, Pages 1015-1023
Biological Psychiatry

Archival Report
Brain Effects of Cognitive Remediation Therapy in Schizophrenia: A Structural and Functional Neuroimaging Study

https://doi.org/10.1016/j.biopsych.2013.01.017Get rights and content

Background

Cognitive remediation therapy positively affects cognition and daily functioning in patients with schizophrenia. However, studies on the underlying neurobiological mechanisms of this treatment are scarce. The aim of the current study was to investigate functional and structural connectivity brain changes in schizophrenia patients after cognitive remediation therapy using a whole-brain approach that combined functional magnetic resonance imaging and diffusion tensor imaging.

Methods

A randomized controlled trial with 30 schizophrenia outpatients and 15 healthy volunteers. A strategy-learning-based treatment was used as a cognitive remediation therapy. A social skills training that provides useful information about illness management was used as an active control. We investigated changes in the pattern of functional connectivity assessed during an n-back task by tensorial independent component analysis as implemented in the multivariate exploratory linear decomposition into independent components and in the fractional anisotropy index of white matter integrity using tract-based spatial statistics.

Results

Brain networks activation pattern significantly changed in patients exposed to the cognitive treatment in the sense of normalizing toward the patterns observed in healthy control subjects. Additionally, in white matter, they showed an increase in fractional anisotropy index in the anterior part of the genu of the corpus callosum. Cognitive improvement, functional, and also structural changes showed statistically significant correlations.

Conclusions

Improvement in brain functioning detected after cognitive remediation therapy in schizophrenia patients might be based on an increase of the interhemispheric information transfer between the bilateral prefrontal cortexes via the corpus callosum.

Section snippets

Methods and Materials

A controlled, randomized study was carried out with three groups: patients receiving cognitive treatment, patients receiving a different psychological intervention as an active control, and a HC group. Randomization was independently conducted by author C.G. He took no part in the implementation of assignments, the generation of the allocation sequence being his only role. On recruitment, patients were randomly assigned to either CRT or social skills training (SST) using computer-generated

Neuropsychological Outcomes

The result of the overall intent-to-treat analysis with the addition of baseline covariates was significant for time by condition (F2,47 = 3.918; p = .029; effect size .175) and also for different cognitive measures (Table 2). Additionally, univariate analyses showed a beneficial effect of CRT on different cognitive tests and cognitive domains (Figure 2), particularly for executive function (F2,47 = 8.469; p = .001; effect size .314), Verbal Memory (F2,47 = 6.029; p = .005; effect size .236)

Discussion

Patients exposed to the treatment showed a reduction in overactivation of the CEN during task-related responses and also in the deactivation of its anticorrelated DMN suggesting an improvement in the efficiency of both networks. On the other hand, an increase in white matter integrity in the genu of the corpus callosum was found in the CRT group after treatment. Functional and structural changes were correlated in the CRT group participants.

Previous studies have already shown a reduction in

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