Dronabinol for Agitation in Dementia Crossover Trial

The goal of this clinical trial is to study the effects of dronabinol in US Veterans with agitation related to moderate to severe dementia. The main goals of the study are: * To evaluate the efficacy of dronabinol for the treatment of agitation in moderate to severe dementia compared to placebo * To evaluate the safety of dronabinol in the treatment of agitation in moderate to severe dementia compared to placebo Fifty (50) subjects will be given either dronabinol or placebo for 8 weeks. All subjects will then undergo a "washout" phase for 3 weeks, followed by the crossover intervention (i.e. subjects who received placebo during the first phase will receive dronabinol during the second phase, and vice versa). Thus, all participants will be taking dronabinol at some point during the study. During the study, subjects will undergo evaluations for: * Agitation * Cognitive changes * Physical changes (i.e. labs, ekg, physical exam)