Theory of Mind impairments in early course schizophrenia: An fMRI study

Adverse childhood experiences differently affect Theory of Mind brain networks in schizophrenia and healthy controls

Patients with schizophrenia (SZ) show impairments in both affective and cognitive dimensions of theory of mind (ToM). SZ are also particularly vulnerable to detrimental effect of adverse childhood experiences (ACE), influencing the overall course of the disorder and fostering poor social functioning. ACE associate with long-lasting detrimental effects on brain structure, function, and connectivity in regions involved in ToM. Here, we investigated whether ToM networks are differentially affected by ACEs in healthy controls (HC) and SZ, and if these effects can predict the disorder clinical outcome. 26 HC and 33 SZ performed a ToM task during an fMRI session. Whole-brain functional response and connectivity (FC) were extracted, investigating the interaction between ACEs and diagnosis. FC values significantly affected by ACEs were entered in a cross-validated LASSO regression predicting Positive and Negative Syndrome Scale (PANSS), Interpersonal Reactivity Index (IRI), and task performance. ACEs and diagnosis showed a widespread interaction at both affective and cognitive tasks, including connectivity between vmPFC, ACC, precentral and postcentral gyri, insula, PCC, precuneus, parahippocampal gyrus, temporal pole, thalamus, and cerebellum, and functional response in the ACC, thalamus, parahippocampal gyrus and putamen. FC predicted the PANSS score, the fantasy dimension of IRI, and the AToM response latency. Our results highlight the crucial role of early stress in differentially shaping ToM related brain networks in HC and SZ. These effects can also partially explain the clinical and behavioral outcomes of the disorder, extending our knowledge of the effects of ACEs.

Effects of Ziprasidone or Haloperidol on Theory of Mind in Patients With Schizophrenia: A 16-week Pilot Trial

OBJECTIVES

Schizophrenia is associated with impairment in theory of mind (ToM), which is defined as the ability to make judgments about mental states and is related to medial prefrontal cortical activity. Ziprasidone, but not haloperidol, is known to have a protective effect in the medial prefrontal cortex. Thus, we hypothesized that these 2 drugs would have different efficacy in improving ToM task performance in patients with schizophrenia.

METHODS

Patients with a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) diagnosis of schizophrenia matched for sex, duration of illness, and education were randomized to receive ziprasidone (n=30) or haloperidol (n=30). All patients were assessed using the Positive and Negative Syndrome Scale and the Personal and Social Functioning Scale. ToM was assessed using a first-order false belief task, a second-order false belief task, the faux-pas task, and the Reading the Mind in the Eyes Task, in order of developmental complexity and difficulty. The primary outcome was change in ToM performance from baseline to 16 weeks of treatment.

RESULTS

For the first-order false belief task, there were no significant differences between the groups (P>0.05). For the second-order false belief task, the interaction effect was significant (P<0.05), and the simple effect of time showed a significant difference only in the ziprasidone group (P<0.001). For the faux-pas task, the interaction effect was not significant (P>0.05). For the Reading the Mind in the Eyes Task, the interaction effect was significant (P<0.05), and the simple effect of time showed a significant difference only in the ziprasidone group (P<0.001). The Positive and Negative Syndrome Scale results were similar between the groups. The ziprasidone group performed better than the haloperidol group on the Personal and Social Functioning Scale. There were no major safety concerns or adverse events.

CONCLUSIONS

The findings of this study suggest that ziprasidone could improve ToM and might be superior to haloperidol for improving complex ToM as well as personal and social functioning in patients with schizophrenia.

TRIAL REGISTRATION CHINESE CLINICAL TRIAL REGISTER

ChiCTR2200060542.