Phenotypic heterogeneity and frequent comorbidity across psychiatric diagnoses complicate efforts to identify causal mechanisms and develop novel treatments for psychopathology, and challenge the diagnostic validity of modern psychiatric nosology. Categorical and dimensional latent variable models, which conceptualize symptoms as passive indicators of underlying disease entities, do not account for phenotypic diversity and dynamic interrelations among psychiatric symptoms. This article reviews the historical and theoretical foundations and current state of the science of network approaches to psychopathology within mood disorders, which reconceptualizes psychiatric disorders as dynamic systems of directly interacting symptoms. The article outlines how symptom network approaches offer alternative explanations for diagnostic heterogeneity, comorbidity, and symptom persistence, drawing on evidence from both nomothetic and idiographic data. Emphasis is placed on potential clinical applications, including case formulation, personalized treatment planning, and outcome monitoring, alongside methodological limitations and translational challenges. Overall, network approaches represent a promising shift toward transdiagnostic, symptom-focused, precision-oriented psychiatric care.
Cunningham et al. (Wed,) studied this question.