Sex Differences in Neuropsychiatric Symptoms in Alpha-Synucleinopathies: A Systematic Review and Meta-Analysis.

Background: Alpha-synucleinopathies, such as Parkinson's disease (PD), Parkinson's disease dementia (PDD), and dementia with Lewy bodies (DLB), demonstrate sex differences with regard to prevalence, age of onset, and motor manifestations. Neuropsychiatric symptoms (NPS) are common early and late manifestations of these disorders.

Objectives: We aimed to describe sex differences in NPS across alpha-synucleinopathies.

Methods: We searched Web of Science Core collection databases to identify observational studies published between January 1, 2000, and June 1, 2022, reporting the prevalence or severity of NPS among individuals with a diagnosis of PD, PDD, or DLB. Prevalence and severity were pooled for each NPS according to sex using random-effects models.

Results: Two-hundred-and-forty studies, representing 796,026 participants (45% females), were included in the meta-analysis. Female sex was associated with a higher prevalence of anxiety (OR = 1.60 [95% CI: 1.40, 1.82]), depression (OR = 1.56 [1.45, 1.67]), fatigue (OR = 1.21 [1.02, 1.43]), and psychotic symptoms (OR = 1.26 [1.14, 1.40]) and more severe anxiety (g = 1.35 [95% CI: 0.58, 2.13]), depression (g = 1.57 [1.05, 2.08]), and fatigue (g = 0.86 [0.41, 1.32]), while male sex was associated with a higher prevalence of apathy (OR = 0.77 [0.63, 0.93]), impulse control disorders (OR = 0.67 [0.55, 0.82]), REM sleep behavior disorder (OR = 0.54 [0.42, 0.70]), hypersomnolence (OR = 0.67 [0.56, 0.80]), and suicide (OR = 0.30 [0.20, 0.44]).

Conclusions: NPS have different prevalences and severities in alpha-synucleinopathies according to sex. These findings support consideration of sex in the elaboration of clinical tools.