Seeking proxies for internal states (SPIS): Towards a novel model of obsessive-compulsive disorder

The Seeking Proxies for Internal States (SPIS) model of obsessive-compulsive disorder (OCD) proposes an account of OCD symptoms in terms of two core components: attenuation of access to internal states and seeking proxies for internal states. Specifically, the SPIS model posits that OCD is associated with difficulty in accessing various internal states, including feelings, preferences, memories, and even physiological states. This difficulty drives obsessive-compulsive individuals seek and rely on compensatory proxies, or substitutes, for their internal states. These proxies are perceived by the individual with OCD to be more easily discernible or less ambiguous compared to the internal states for which they substitute, and can take the form of fixed rules, rituals, or reliance on external sources of information. In the present article we first provide a detailed explanation of the SPIS model, and then review empirical studies that examined the model in a variety of domains, including bodily states, emotions, and decision-making. Next, we elaborate on the SPIS model's novel account of compulsive rituals, obsessions and doubt and relate them to extant theoretical accounts of OCD. To conclude, we highlight open questions that can guide future research and discuss the model's clinical implications.