The refinement of the Williams syndrome phenotype has frequently included the study of behavioral and temperamental features common to individuals with this disorder. Within this line of research, the importance of evaluating incidence of psychopathology has been increasingly recognized, with studies consistently identifying an increased risk for anxiety and attentional disorders in this population. However, there has been little research about the treatment of these difficulties. In this article, we review the literature about mental health in people with Williams syndrome, outline the need for mental health treatment in Williams syndrome that is informed by the cognitive and behavioral phenotype, and highlight issues to consider when designing such interventions based on case examples. (Contains 7 figures and 3 tables.)