Alexithymia in Schizophrenia and Psychosis Vulnerability: A Systematic Review and Meta-Analysis.

Aims: Disturbances involving impairments in experience and expression of affect are frequently identified in schizophrenia samples. Alexithymia underlies cognitive impairments in identification and expression of affect, further implicated in affect dysregulation. The current review aimed to systematically review the literature and estimate the strength of associations between alexithymia and schizophrenia phenomenology.

Method: A systematic review and meta-analysis identified 67 studies involving measures of alexithymia in psychosis. All studies were assessed for quality and publication bias. Overall, data from 47 studies were suitable for meta-analysis.

Results: Alexithymia and schizophrenia were consistently positively associated with a large effect size (k = 11). Compared to control groups, a schizophrenia diagnosis was positively associated with large magnitude effects for difficulties in identifying feelings (k = 18) and moderate effect sizes for difficulties in describing feelings (k = 17) and externally oriented thinking (k = 11). Data from community samples indicated moderate associations between subclinical negative symptoms and difficulties in identifying and describing feelings (k = 4) and a small association between positive symptoms and difficulties in identifying feelings (k = 5).

Conclusions: Alexithymia and schizophrenia are strongly associated. However, methodological issues limit the establishment of directionality in these associations. The majority of studies use cross-sectional designs reliant on self-report assessments which may result in over-estimation of the reported effect sizes. Future research could conceptualize alexithymia as a stress-reactive multidimensional construct, and modeling dynamic relationships between alexithymia, psychological distress, and schizophrenia phenomenology should incorporate confounders such as gender, age, and neurocognition.