Functional connectivity in neuropsychiatric diseases

Neuropsychiatric disorders arise from disruptions in cognitive, affective, and behavioral integration, along with impaired neural coordination across brain regions. Over the past decade, the study of functional connectivity (FC) has transformed our understanding of these conditions, shifting the focus from localized dysfunctions to large-scale network disruptions. This chapter explores resting-state FC (Rs-FC) as a crucial tool for investigating psychiatric disorders, including schizophrenia, major depressive disorder, bipolar disorder, obsessive-compulsive disorder (OCD), and post-traumatic stress disorder. We review key findings from functional magnetic resonance imaging, positron emission tomography, electroencephalogram, and magnetoencephalography studies, highlighting common dysconnectivity patterns in the default mode network, salience network, and executive-control network. Additionally, FC-based approaches offer valuable insights into therapeutic interventions, shedding light on the effects of pharmacological and neuromodulator treatment on brain network dynamics. The integration of multimodal neuroimaging techniques enhances our understanding of psychiatric disorder pathophysiology, paving the way for personalized and network-targeted interventions.