Psychiatric symptoms as pathogens

Abstract

Disorders are typically seen as the causes of their symptoms. This makes sense in many fields of medicine, but not in psychiatry where symptoms constitute disorders: the notion that mental disorders cause symptoms is a tautology. Biological psychiatry tries to circumvent this logical fallacy by trying to identify pathophysiological parameters that are specific to given disorders. Unfortunately, research has not resulted in biological markers that reliably discriminate patients who suffer from a disorder from those that do not. A different approach is to regard psychiatric symptoms not as ‘output’ from underlying, yet to be identified (pathophysiological) dysregulation, but to consider symptoms as “input” that causally contributes to other symptoms. Fresh insights, mathematical methods and empirical data come from network analyses, derived from physics. These network approaches, treating “symptoms as input” converge with work in Cognitive Behavior Therapy and in Experimental Psychopathology. This convergence is illustrated with experimental work on Obsessive Compulsive Disorder. It is argued that data and concepts from network theory provide a sound conceptual rationale for treating symptoms as input and that network theory,