Aims
Apathy is an important feature of Lewy body dementia (LBD). Existing data on the prevalence of apathy in LBD is heterogenous. Therefore, we aimed to estimate the prevalence of apathy in LBD through systematic review and meta-analysis.
Methods
Five databases were searched for relevant articles using key terms “Lewy body”, “Parkinson’s disease dementia” (PDD), “mild cognitive impairment” (MCI), “neuropsychiatric symptoms”, “apathy”, and their synonyms. Articles reporting prevalence of apathy in MCI and dementia stages of dementia with Lewy bodies (DLB), PDD and LBD were included. Random effect meta-analysis was performed to determine prevalence of apathy.
Results
The search identified 7477 articles, 46 met the inclusion criteria. The pooled prevalence of apathy in LBD (DLB and PDD, n = 3940) was 58% (95% confidence interval (CI) 51 – 64%, I2 = 95.3%), in DLB (n = 2169) 58% (95% CI 52 – 64%, I2 = 86.5%) and in PDD (n = 1557) 56% (95% CI 43 – 70%, I2 = 97.6%). The pooled prevalence of apathy in LB-MCI (n = 316) was 49% (95% CI 34 – 65%, I2 = 88.4%) and PD-MCI (n = 337) was 40% (95% CI 29 – 51%, I2 = 51.1%).
Conclusion
Apathy is an important and prevalent feature of LBD throughout the disease continuum. High prevalence of apathy in prodromal disease supports its utility in early DLB diagnosis. Future research should prospectively validate apathy as a component of diagnostic criteria in prodromal disease and focus on earlier identification and management of apathy in LBD.