The aim of the current study was to explore why some individuals with dementia and agitated behavior showed limited response to a personalized intervention. Ten consistently agitated individuals (i.e., non-responders) were compared with 34 individuals who were more settled during the intervention (i.e., responders). Most participants had severe cognitive deficits; however, non-responders were more impaired. Where responders showed large improvements across conditions, agitated behavior remained equally high in nonresponders. Responders and non-responders showed increased interest and engagement during the intervention. Increased agitated behavior was associated with severe cognitive impairment. Although studies have shown that psychosocial interventions can reduce agitated behavior, there does seem to be a point where it becomes more difficult to reduce this behavior. However, nonresponders still displayed interest, and the authors believe further personalization of the intervention is possible. Therefore, severe dementia and agitated behavior should not exclude individuals from psychosocial interventions; however, a more detailed and timely implementation plan of such treatments may be warranted.