Background: Behavioral and Psychological Symptoms of Dementia (BPSD) are core and highly detrimental symptoms of dementia. Previous research has suggested a potential association between pain and BPSD, but pieces of evidence are lacking.

Objective: This study aimed to investigate the association between pain and BPSD in patients with dementia.

Methods: Seven databases were searched from inception to February 2024, including PubMed, Web of Science, Embase, CINAHL, Cochrane Library, China National Knowledge Infrastructure (CNKI), and WanFang Data. Cross-sectional and longitudinal studies were included. We included studies that involved older adults with dementia and assessed the pain and BPSD by using validated tools. The quality of cohort studies was assessed using the Newcastle-Ottawa Scale, and the quality of cross-sectional studies was evaluated using AHRQ criteria. Two researchers independently screened the articles, extracted the data, and assessed the quality of the studies. A meta-analysis was conducted using Stata 15.0. Data not suitable for meta-analysis was analyzed through a qualitative synthesis to provide a comprehensive overview of the findings.

Results: A total of 12 studies were included, comprising nine cross-sectional studies and three longitudinal studies. All studies were of medium to high quality. Studies reported that pain was associated with 13 different types of BPSD, including agitation, aggression, abnormal thought process, anxiety, care refusal, delirium, depression, delusions, hallucinations, sexual disinhibition, sleep disturbances, socially inappropriate behavior, and wandering. A pooled odds ratio (OR) of 1.25 (95%CI [1.17,1.33], p < 0.001) indicated a significant positive association between pain and BPSD. Specifically, pain was positively associated with aggression (OR = 1.07, 95%CI [1.00,1.13], p = 0.035), agitation (OR = 1.17, 95%CI [1.14, 1.21], p < 0.001), and depression (OR = 2.11, 95%CI [1.76,2.52], p < 0.001). However, pain was significantly negatively associated with wandering (OR = 0.77, 95%CI [0.73, 0.81], p < 0.001).

Conclusions: Pain was significantly positively associated with BPSD in patients with dementia, specifically with aggression, depression, and agitation. However, pain was negatively associated with wandering. This emphasizes the importance of further research in this area and improved interventions for pain and BPSD management.

Trial registration: www.crd.york.ac.uk CRD42023432320, registered 08/08/2024.