This article provides a critical viewpoint on Loughran’s recent work in Medicine, Science and the Law on the causes of the rise in the police’s use of section 136 (s136) of the Mental Health Act 1983 (Loughran M. Detention under section 136: why is it increasing? Med Sci Law 2018; 58: 268–274). The rate of this rise seems significant: by 2014, it was five times more likely that a person in England would be detained in a hospital under s136 than it was in 2000, and the trend has continued to the present day. This viewpoint considers the significance of the s136 rise from the theoretical perspective of causal analysis.