Since Descartes introduced dualism, body and mind have been seen as separate entities. The latent disease model, the view that symptoms are caused by an underlying disease, was possible within the dualistic paradigm. This paradigm, although successful in some aspects of medicine, is also assumed to underlie psychiatric disorders. As an alternative to the latent disease model, the network approach conceptualizes disorders as complex networks of causally connected symptoms. It offers a new way of understanding psychiatric disorders by directing attention away from the underlying cause and towards the symptoms and their functional interconnectedness, making the distinction between mental and physical symptoms obsolete. This article discusses how the network perspective helps us to overcome some of the problems we have faced when diagnosing and treating psychopathology in the medically ill. Furthermore, we describe how the network perspective can stimulate new research to better understand psychopathology in medically ill patients and how it can help deliver the most suitable treatment to the individual patient.