The Three-Dimensional Approach to Neuropsychiatric Assessment

Brain–behavior relationships form the foundation for clinical assessment in neuropsychiatry and behavioral neurology. The complexity of the brain and its clinical disorders makes it important to have a systematic and useful way to apply them. This article introduces the three-dimensional approach to neuropsychiatric assessment (3DA), a process-based approach to integrating brain–behavior relationships into clinical activity. The 3DA is a simple, four-step process for teaching these relationships and their clinical use. The four steps are 1) Explain the principle of localization; first, as applied in general neurology; then, as applied to behavioral neurology and neuropsychiatry; 2) Review brain–behavior relationships in three dimensions: laterality (left–right), anteriority (anterior–posterior), and verticality (cortical–subcortical); 3) Introduce the “frontal–subcortical paradox” (subcortical dysfunction may cause what many know as “frontal lobe” signs) and its explanation (the neurobehavioral correlates of the frontal–subcortical circuits); 4) Present model disorders for the three dimensions. The presentation describes the rationale and approach for using the 3DA to teaching neuropsychiatry and behavioral neurology.