Effects of Cognitive Stimulation Intervention on Cognitive Function and Depression in Older Adults with Mild Dementia: A Quasi-Experimental Study

Background: Cognitive stimulation therapy (CST) is a non-pharmacological intervention designed to improve cognitive function and emotional well-being in individuals with dementia. However, limited studies have evaluated its efficacy in Chinese-speaking populations. This study aimed to assess the effects of a 12-week cognitive stimulation intervention on cognitive function and depression in older adults with mild dementia. Methods: This quasi-experimental study employed a repeated measures design with a non-randomized experimental and control group. Participants (N = 40) 65 years and older with mild dementia (clinical dementia rating (CDR) = 0.5–1) were recruited from a regional hospital and dementia care center in Taiwan. The experimental group (n = 20) received a structured CST intervention for 12 weeks (two sessions per week, 120 min per session), while the control group (n = 20) received routine care. Cognitive function was assessed using the Saint Louis University Mental Status (SLUMS) exam, and depression was measured using the Chinese version of the Cornell Scale for Depression in Dementia (CSDD-C). Data were collected at baseline, 4, 8, and 12 weeks and analyzed using repeated measures ANOVA and generalized estimating equation (GEE) modeling. Results: The experimental group showed significant improvements in cognitive function compared to the control group (SLUMS score: baseline 16.1 ± 4.8 to 12th week 19.3 ± 5.0, p < 0.001). Depression levels decreased significantly in the experimental group but not in the control group (p < 0.05). The GEE analysis showed that the improvement in cognitive function was positively associated with education level and duration, but declined with increasing age. Similarly, depression was lower in participants with higher educational levels and in men. Conclusions: The findings support the efficacy of CST in improving cognitive function and reducing depression in older adults with mild dementia. The results highlight the importance of the duration of the intervention and individual cognitive reserve in modulating treatment outcomes.