Association between alexithymia and non-suicidal self-injury in psychiatric patients: the mediating role of self-esteem and the moderating role of emotional intelligence

Background: Raffagnato's theory claims that if people have no words to express their emotions (alexithymia), they express themselves by venting or through non-suicidal self-injury (NSSI). However, these associations have not been confirmed in psychiatric patients. This study explored the relationship between alexithymia and NSSI in psychiatric patients and the potential underlying psychological mechanisms. Methods: This retrospective study involved face-to-face interviews with 449 outpatients consecutively recruited from West China Hospital. Alexithymia, self-esteem, NSSI, and emotional intelligence (EI) were measured. The moderating role of EI and the mediating role of self-esteem between alexithymia and NSSI were also explored. Logistic regressions were used to examine whether sociodemographic, clinical variables and alexithymia were independently associated with NSSI. Results: The DSM-5 NSSI disorder and alexithymia prevalences were found to be 32.5% and 45.2%. When the other covariables were controlled for, the alexithymic patients were found to be at increased odds (OR 2.76) of engaging in NSSI behaviors. These results confirmed the strong associations between alexithymia, low self-esteem, and NSSI risk. Lower EI was found to be related to the connections between alexithymia and NSSI. Except for the lower risk in anxiety patients, the risk of NSSI was similar for patients with other mental disorders, Conclusion: This study revealed the psychological mechanisms through which alexithymia increases the risk of NSSI. Therefore, to reduce NSSI risk, screening for alexithymia should be emphasized. Self-esteem as a targeted psychological intervention could also assist in mitigating the process from alexithymia to NSSI behaviors, and EI training for psychiatric patients could weaken the relationship between alexithymia and NSSI.