This randomized, controlled, longitudinal clinical trial investigates the effects of Snoezelen Multisensory Therapy (SMT) as an adjunct to standard therapy (ST) in older adults with dementia. Sixty participants with mild to moderate cognitive impairment and behavioral and psychological symptoms of dementia (BPSD) will be recruited from the Center for Older Adults Lucija (Slovenia). Participants will be randomized into two groups: control (ST) and experimental (ST + SMT). SMT will be administered 3 times per week for 12 weeks. Primary outcomes include changes in agitation (CMAI), depression (CSDD), anxiety (HADS), physiological indicators (heart rate, HR variability, SpO2, skin conductance, salivary cortisol), and frequency of psychiatric medication use. Subjective well-being will also be tracked before and after each session.