Differential aberrant connectivity of precuneus and anterior insula may underpin the diagnosis of schizophrenia and mood disorders

Abstract

BACKGROUND Over the past decade, resting-state functional magnetic resonance imaging (rs-fMRI) has concentrated on brain networks such as the default mode network (DMN), the salience network (SN), and the central executive network (CEN), allowing for a better understanding of cognitive deficits observed in mental disorders, as well as other characteristic psychopathological phenomena such as thought and behavior disorganization. AIM To investigate differential patterns of effective connectivity across distributed brain networks involved in schizophrenia (SCH) and mood disorders. METHODS The sample comprised 58 patients with either paranoid syndrome in the context of SCH ( n = 26) or depressive syndrome (Ds) ( n = 32), in the context of major depressive disorder or bipolar disorder. The methods used include rs-fMRI and subsequent dynamic causal modeling to determine the direction and strength of connections to and from various nodes in the DMN, SN and CEN. RESULTS A significant excitatory connection from the dorsal anterior cingulate cortex to the anterior insula (aI) was observed in the SCH patient group, whereas inhibitory connections from the precuneus to the ventrolateral prefrontal cortex and from the aI to the precuneus were observed in the Ds group. CONCLUSION The results delineate specific patterns associated with SCH and Ds and offer a better explanation of the underlying mechanisms of these disorders, and inform differential diagnosis and precise treatment targeting.

Chronic tobacco smoking, impaired reward-based decision-making, and role of insular cortex: A comparison between early-onset smokers and late-onset smokers

“…According to Lüscher et al (76), the symptoms listed in DSM-V for SUD reflect a compulsive behavior which is characterized by an excessive time spent searching for the drug of abuse when it is not available, by the prioritization of the search for the drug of abuse over other activities (e.g., familial, social, work-related), by a failure to avoid self-harm, and by the craving for the substance of abuse. Belin-Rauscent et al (74), who defined the insula as "the neurobiological gate for the development of compulsive behavior, " revealed lower cortical thinness in the bilateral insula of 140 rats to be causally related to heightened motor disinhibition and compulsivity as assessed by a five-choice serial reaction time task (80,81).…”

Alterations of Static and Dynamic Functional Connectivity of the Nucleus Accumbens in Patients With Major Depressive Disorder

“…The DMN is involved in spontaneous cognition, self-referential processing, and affective decision making ( 64 ). For instance, the precuneus is involved in cognitive control functions including visual imagery and self-orientation processes and is further engaged in the integration of mental processing ( 65 ). Multiple investigations have repeatedly demonstrated the abnormality of DMN in patients with MDD ( 66 – 68 ).…”

“…The VLPFC is associated with reward processing and it is abnormally activated in patients with Bipolar Disorder ( 76 – 78 ). The insula is the hub of large-scale brain networks interaction that is involved in externally oriented attention and self-cognition ( 65 ), one study found that the insula is associated with the value of action, and the insula is associated with seeking reward-related decisions ( 79 ). Thus, the abnormalities in the functional connectivity of the NAc with the VLPFC and insula may be that they do not support NAc function.…”

Perspectives before incremental trans-disciplinary cross-validation of clinical self-evaluation tools and functional MRI in psychiatry: 10 years later

“…The results from direct comparison yielded significant residual activation clusters in the middle frontal gyrus after family-wise error correction. This result may indicate that the high depression score in terms of self-evaluation corresponds to a specific pattern of brain activation, which is also related to dysfunctional connectivity of the same region at rest (32,33).…”

“…The results demonstrated significant residual activations in the precuneus and angular gyrus areas, which were considered diagnostically relevant ( 37 ). Those activations are considered to be in the default mode network, which means that there is essentially an aberrant activation in that system in schizophrenia ( 32 , 33 , 38 ). In such a way, we have attempted to integrate the two methods: the clinical self-assessment scale and functional MRI, with the intention of achieving incremental trans-disciplinary validity of both methods.…”