Anxiety disorders, as defi ned in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), comprise a relatively heterogeneous group of clinical conditions that range from specifi c phobias to obsessive compulsive disorder (OCD) and post-traumatic stress disorder (PTSD). The grouping under one heading refers to the fact that these seemingly heterogeneous disorders share a number of common psychopathological features and also share at least some common principles in treatment. Among the shared elements are broadly defi ned prototypical anxiety reactions, panic attacks, anticipatory anxiety, avoidance behaviour, a predominantly early onset, and relatively high persistence rates over time. Many of the shared diagnostic features of anxiety disorders are by their nature dimensional, and hundreds of psychometric scales have been developed to measure these diagnostic constructs across anxiety disorder and for specifi c diagnostic classes. This paper explores different types of dimensional approaches used in the literature and discusses how an integrated categorical/dimensional strategy might enhance the usefulness of the DSM-V. We suggest the use of cross-cutting dimensional ratings that might ultimately lead to an improved classifi cation model. We also suggest that a staging approach to illness, based upon supplementary dimensional rating could provide useful information for clinical and research purposes.