How Psychological Trauma Affects Cognitive Functions: A Systematic Review and Meta-Analysis

Objective: Promising research has investigated the relationships between psychological trauma and cognitive impairments, resulting in deficits of information processing, attention or memory. From a clinical point of view, investigations regarding the potential associations between cognitive outcomes and trauma appear useful to draw informed clinical indications for practitioners. However, the current lack of systematization of the existing literature makes difficult to frame in a comprehensive perspective the results brought by empirical research. Method: PRISMA principles were used to perform a systematic search on MEDLINE, PubMed, PsycINFO, PsycARTICLES, Scopus and Web of Science databases. Studies were screened and selected using inclusion/exclusion criteria defined in a PICOS format. Results: The initial search identified 75.245 records and led to the final inclusion of 29 independent contributions assessing between-group differences considering differences according to trauma exposure or posttraumatic stress disorder diagnosis. After the extraction and codification of information and the computation of effect sizes, a series of meta-analyses were performed using a random effects model. Data confirm a significant impact of psychological trauma on cognitive domains, indicating that individuals who experienced traumas show worse cognitive functioning, particularly in the attention and executive functions domains. Moreover, meta-analyses reported that in the case of posttraumatic stress disorder, there are more cognitive domains impaired, including memory, processing speed, visuospatial processing, and global cognitive functioning. Conclusions: The study confirms a direct association between trauma and cognitive functioning, suggesting the importance of further studies examining the characteristics of the traumatic experience to provide clear clinical guidelines.