Abstract Objective Traumatic brain injury (TBI) is frequently associated with persistent sleep disturbances, which may compound neurocognitive impairments, particularly in processing speed. This meta-analysis examined the relationship between sleep quality and cognitive processing speed in adults with a history of TBI. Method A systematic literature review was conducted using PubMed and PsycINFO for peer-reviewed studies published between 2000 and 2024. Studies were included if they reported quantitative processing speed outcomes in TBI populations with documented sleep disturbances. Of 38 screened articles, seven met inclusion criteria. Cognitive assessments included the Trail Making Test (TMT), WAIS-IV Processing Speed Index, Coding subtest, and Symbol Digit Modalities Test (SDMT), while sleep disturbances were measured via the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), STOP-BANG, and polysomnography. Results A fixed-effect meta-analysis across studies using PSQI and ISI yielded a significant association between sleep quality and processing speed: r = .57, 95% CI .47, .65, z = 9.41, p .001. Individual studies consistently reported that poorer sleep was associated with slower processing speed, with effect sizes ranging from r = .22 to r = .60. Several studies accounted for demographic covariates such as age, psychiatric comorbidities, and education, strengthening the reliability of observed associations. Conclusion Limitations include the use of a fixed-effect model due to the small number of included studies, which precluded valid meta-regression. Heterogeneity across sleep and cognitive measures also limits generalizability. Findings support the impact of sleep disturbance on cognitive recovery post-TBI, highlighting the need for sleep-targeted interventions in future research.
Chhatriwala et al. (Fri,) studied this question.