Self-related networks and negative symptoms in psychotic disorders

Abstract

Objective

Two factors of negative symptoms in schizophrenia have been consistently described based on factor analysis, “expressive deficits” and “social amotivation”. We aimed to investigate the putatively differential involvement of self-related networks, as measured with BOLD fMRI during a self-evaluation task, in two dimensions of negative symptoms in schizophrenia (reduced expression and social amotivation).

Method

Forty-five patients with a diagnosis of schizophrenia participated in an fMRI study in which they performed a self-evaluation task. The task comprised a self-reflection, close other-reflection, and a semantic (baseline) condition. We compared correlates of Expressive versus Social amotivation factors (summed items from the PANSS interview) for the contrasts self-baseline and self-other. Significance threshold was set at P < 0.05 family-wise error (FEW) corrected.

Results

Social amotivation correlated significantly with self-evaluation vs. baseline in right and left ACC, and in the sulcus of frontal lateral lobe between inferior frontal triangularis and middle frontal gyrus. This was also significant, but less pronounced, in the direct comparison of social amotivation vs. expressive deficits scores (for the self-baseline contrast). No activation differences survived critical thresholds for the self-other contrast.

Conclusion

Differential neural correlates for the two dimensions of negative symptoms support the validity of this distinction based on factor analyses. Intact functioning of brain circuitry for self-referential processing may be of relevance to actively seek social interaction.

Disclosure of interest

The author has not supplied his declaration of competing interest.