Abstract

Insomnia significantly impacts mental health by intensifying negative emotions. It has been proposed that insomnia may also contribute to negative self-evaluation and self-disgust, potentially leading to nonsuicidal self-injury (NSSI). This study explored whether the connection between insomnia and NSSI is mediated by both negative affect (including depression, anxiety, and overall negative feelings) and self-disgust. We analyzed the individual mediating effects of anxiety and depression while also assessing the combined influence of overall negative affect. Our participants included 300 adults (63.7% female, 36.3% male; Mage = 34.76, SD = 11.02) with a history of NSSI, recruited from across the country. Data collected through self-report measures were examined using Model 6 of the PROCESS macro. The results showed that in all three models, the relationship between insomnia and NSSI was significantly mediated by both negative affect (anxiety, depression, and overall negative affect) and self-disgust. These findings emphasize the need to address both negative emotions and self-disgust in psychological interventions aimed at treating comorbid insomnia and NSSI, highlighting the necessity for a multifaceted approach to NSSI prevention.