The Prevalence and Characteristics of Alexithymia in Adults Following Brain Injury: A Meta-Analysis

Alexithymia is the inability to identify and describe one's own emotions. Some research suggests that organic alexithymia may occur after acquired brain injury (ABI). However, the results in the literature are inconsistent, when comparisons are made against healthy controls. Furthermore, a precise estimate of alexithymia prevalence in the ABI population has not yet been reported. Consequently, this meta-analysis aimed to estimate the prevalence and characteristics of alexithymia in ABI, as measured by the Toronto Alexithymia Scale-20 (TAS-20). Based on 22 unique ABI samples, a series of random-effects meta-analyses estimated moderate to large positive effect sizes (i.e., greater alexithymia in ABI samples) for the TAS-20 total scale (Hedges' g = 1.00, 95% CI [0.75, 1.35]), as well as the subscales: difficulty identifying feelings (Hedges' g = 0.92, 95% CI [0.66, 1.17]), difficulty describing feelings (Hedges' g = 0.69, 95% CI [0.50, 0.87]) and externally oriented thinking (Hedges' g = 0.75, 95% CI [0.64, 0.85]). Furthermore, a meta-regression identified a larger effect size (TAS-20 total scale score) for traumatic brain injury (TBI) samples, in comparison to non-TBI samples. Finally, the prevalence of clinically significant levels of alexithymia (TAS-20 total scale ≥ 68.4; i.e., two SDs above the general population mean) in ABI patients was estimated at 15.2%. We interpreted the results to suggest that ABI may have a substantial negative impact on affective processing abilities and, thus, comprehensive assessment of emotional functioning deficits following ABI should be considered by practitioners.