Abstract

Obsessive-compulsive disorder (OCD) is an extremely disabling psychiatric illness characterised by intrusive thoughts and compulsive stereotyped behaviours. The current neurobiological model of OCD (the habit model) proposes that compulsions result from a disrupted balance between two distinct but interactive brain systems: the goal directed system, which supports behaviours that are intentional and sensitive to goal value and the habitual system, which underlies more automatic actions. This imbalance favours the habitual system, hence OCD has been characterised as a disorder of maladaptive habit learning. Although promising, the habit model needs further testing. First, habits in OCD were never measured directly, probably because of the extended training required for habit development. Greater habit learning has only been inferred based on impaired goal-directed control but this does not necessarily mean that the habit system gains control over behaviour, especially given their dissociable neural substrates. Second, the mechanism by which habits become compulsions has yet to be specified. In this talk I will review previous studies which led to the habit model of OCD and discuss why it is crucial to address its limitations, looking beyond habit formation to explore habit perseveration. I will further present a new project that aims to capitalize on mobile phone technology to create real habits in the laboratory in order to understand how the brain arbitrates between intentional and automatic actions after habits are established.