Impaired functional neuronal connectivity in schizophrenia negative symptoms

Schizophrenia (SZ) negative symptoms constitute a significant clinical challenge in everyday clinical practice, as most of them are persistent and unresponsive to standard psychopharmacotherapy. Recently, the role of brain network functional connectivity disturbances has been emphasized as a potential underlying mechanism for their occurrence and severity. This review aims to synthesize selected findings on altered brain network functional connectivity patterns associated with negative symptoms of SZ. Several distinctive functional dysconnectivity patterns have been identified in relation to particular SZ negative symptoms presence or severity. Particular attention has been given to cortico-limbic, cortico-striatal and cortico-basal ganglia circuits, with an emphasis on the role of the lateral prefrontal cortex, as well as altered cerebellar-cerebral functional connectivity. Although studies have already demonstrated a link between alterations in brain network functional connectivity and negative symptoms of SZ, it remains unclear whether observed disturbances play a central role in the development of the SZ, or if they are secondary abnormalities to other pathological processes contributing to its clinical course. Moreover, the identification of one and unified pattern of the functional neuronal dysconnectivity, responsible for the occurrence, persistence and severity of particular negative symptoms, is difficult due to the heterogeneity of SZ presentations and methodological limitations of already conducted studies. Future empirical studies are highly recommended to discover more deeply interactions between impaired neural functional connectivity and schizophrenia symptoms.