INTRODUCTION
What is the nature of psychopathology? The currently dominant view is exemplified in the Diagnostic and Statistical Manual of Mental Disorders (DSM), which offers standard criteria for the classification of mental disorders.1 These criteria (that is, symptoms) are believed to be manifestations of an underlying entity (that is, the disorder), just as physical complaints are manifestations of a physical disease. This perspective is called the ‘common cause approach’ and has dominated mental health clinical practice and research.
There have been several criticisms of this approach, including the questionable validity, reliability, and utility of psychiatric diagnoses.2,3 This is apparent from the striking heterogeneity in symptom profiles and course trajectories within the diagnostic categories,4,5 and high comorbidity across categories.3 Furthermore, neither neuroscience studies nor genetic studies have demonstrated biological causes convincingly.6 Another important critique is that the differential characteristics of individual symptoms and their potential causal relations are neglected.7 Finally, translating symptoms of distress into categories of psychopathology can medicalise everyday problems.6
In recent years the network approach has offered an alternative way of thinking about mental health problems.8 This approach conceptualises psychopathology as a dynamic system of causally related symptoms; it is not the mental disorder that provokes the symptoms, but symptoms that provoke or reinforce other symptoms. Several studies have applied the network approach to examine the nature of mental health problems in large epidemiological databases and longitudinal data of …