Evaluating the complex systems approach to persisting post-concussion symptoms

Persisting post-concussion symptoms (PPCS) refers to a heterogenous cluster of difficulties experienced by a significant proportion of individuals following mild traumatic brain injury (mTBI). Innovative developments by Kenzie et al. suggest that PPCS may be understood as a complex dynamical system, with persisting symptoms being maintained by interacting factors across the brain, experience, and social environment. This paper offers a conceptual and theoretical evaluation of Kenzie et al.’s model, based on a broad set of appraisal criteria drawn from the philosophy of science. Kenzie et al.’s model is found to have several strengths. Areas for improvement highlighted include recognising the role of bodily factors outside the brain, improving the specificity and perceived importance of psychological and contextual factors, and managing the complexity of the model. Four suggestions are then made for continued development of a complex systems approach to PPCS. These include drawing on an enactive understanding of human functioning, utilising the notion of a “scientific phenomenon” to improve specificity, making riskier psycho-social hypotheses, and developing component models targeted at clinical phenomena.