Gerdner and colleagues33,34 developed an intervention to decrease behavioral disturbance and increased pleasant events for individuals with dementia based on the theory of Progressively Lowered Stress Threshold (PLST). PLST is based on the premise that as dementia progresses, the affected individual's ability to adapt to environmental and interpersonal stressors decreases. This approach teaches family caregivers problem-solving strategies to identify and provide activities that are appropriate for the individual's current level of functioning and to implement environmental modifications that support ADL function. In a randomized controlled trial of this approach, 237 caregiver/care recipient dyads from 8 research sites were randomly assigned to the PLST program (n = 132) or a usual care control group (n = 105). At the 12-month assessment, in comparison with the control group, the PLST group had significantly lower caregiver distress over behavior problems, and for nonspouses, the frequency of behavior problems was also significantly lower. Another version of this approach has also been applied in a randomized controlled investigation of 48 caregiver-care recipient dyads in Taiwan by Huang and colleagues,35 and resulted in significantly reduced agitation in the treatment group in comparison with a control condition.