During the past decade, the concerns of psychological research within alcohol studies have been far ranging and even within the areas of personality and neurocognition, the literature is voluminous and many faceted. This chapter focuses on aspects of the personality system that appear to increase vulnerability to excessive alcohol or other drug use or the experience of use-related problems as well as issues related to temporal stability and change in intrapersonal development and drinking behaviors. The bulk of the neurocognitive literature reviewed deals with the impairments that accrue as a direct or indirect consequence of excessive alcohol consumption. While the individual empirical studies are often, by necessity, narrow in focus, the import of intrapersonal sources of vulnerability and the processes and mechanisms through which these may drive and moderate alcohol and other drug use behaviors and outcomes will be more fully understood within the context of conceptual models and research approaches that are complex, multilevel, and integrative.