In this chapter we will focus on dimensional constructs of impulsive versus compulsive behaviors and their interface with aggression in relation to pharmacotherapy. Like so many other psychopathological states, impulsivity and compulsivity are not pathognomonic of any particular categorical diagnostic entity and may fit within the broader constellation of numerous conditions that affect mood, development, personality, addiction, cognition, and perception. Particular issues arise when considering trait versus state features of psychopathology and environmental factors that may exacerbate or otherwise contribute to an underlying diathesis.

We will begin with some definitions, followed by a quick review of pertinent neural circuitry that bears on relevant psychopathology and psychopharmacology (Box 14.1).