Self-criticism is a real-time predictor of non-suicidal self-injury and disordered eating: An ecological momentary assessment study among treatment-seeking individuals.

Background: Although theory and research implicate self-criticism as a risk factor for non-suicidal self-injury (NSSI), the nature of this association in daily life remains unclear. This study used ecological momentary assessment (EMA) to address whether (1) trait and state self-criticism elevate the risk of NSSI, (2) state self-criticism predicts NSSI behavior in real-time via increased NSSI urge intensity, and (3) the risk pattern extends to disordered eating (DE; binge eating, purging, restrictive eating).

Methods: A total of 125 treatment-seeking individuals who self-injure (87.20% female; M_age = 22.98, SD = 5.32) completed measures of trait self-criticism at intake, followed by six daily assessments for 28 days (15,098 assessments; median compliance = 78.6%) measuring self-critical thoughts, NSSI, and DE. Multilevel vector autoregressive models were constructed within a dynamic structural equation modeling framework.

Results: Patients who reported higher mean state self-critical thoughts experienced more intense NSSI urges and an increased risk for NSSI behavior during the 28-day EMA period. Higher-than-usual self-critical thoughts predicted NSSI urge intensity and NSSI behavior within the following 2 h. NSSI urge intensity partially mediated the effect of self-critical thoughts on NSSI behavior. Trait self-criticism did not predict comorbid DE, but mean state self-critical thoughts were associated with binge eating and restrictive eating. The within-person risk pattern of self-criticism generally extended to DE, with full mediation via DE urges for purging and restrictive eating, but not binge eating.

Conclusions: Self-criticism is a real-time predictor of NSSI and comorbid DE. These findings underscore the relevance of monitoring self-criticism outside the therapy room, as it may be an important treatment target.