Mental disorders are more and more seen as based on complex networks of symptoms and predispositions that create the disorder as an emergent behaviour of the network’s dynamics. This paper aims to provide a computational model reflecting the adaptive causal relations between anxiety, stress and physical exercise based on a network-oriented modelling approach. The model was evaluated by executing several simulations and validated through an examination of its emergent properties and their cross-reference to the available literature. The created model offers the possibility of simulating different treatments, and offers a basis to develop a virtual patient model.