Mental images, entrapment and affect in young adults meeting criteria of nonsuicidal self-injury disorder (NSSID) – a daily diary study

BACKGROUND: Incidents of nonsuicidal self-injury (NSSI) are often accompanied by mental images which could be perceived as distressing and/or soothing; yet existing data is derived from participants with a history of NSSI using retrospective methods. This study investigated mental images related to NSSI (“NSSI-images”), and their relationship to the proposed Nonsuicidal Self-Injury Disorder (NSSID). METHODS: An e-mail was sent to all female students of the local University providing the link to an online screening and 201 students with a history of repetitive NSSI responded. Nineteen eligible participants meeting criteria of NSSID (mean age = 25; 32% with migrant background) further completed a baseline interview and a ten-day-diary protocol. RESULTS: Among the sample of N = 201, 83.6% reported NSSI-images. In the subsample of n = 19 diagnosed with NSSID, the frequencies of NSSI and NSSI-images were correlated; about 80% of the most significant NSSI-images were either of NSSI or of an instrument associated with NSSI (i.e., a razorblade). In the diary, 53% of the sample self-injured. NSSI-images were reported on 94% of NSSI-days, and on days with NSSI and NSSI-images, the images almost always occurred first; the images were overall perceived as twice more distressing than comforting. Images on NSSI-days were characterized by more comfort, intrusiveness and compellingness yet less vividness, and increased subsequent positive and negative affect compared to non-NSSI days. NSSI-days were further marked by increased entrapment beliefs and increased negative yet decreased positive affect at night. These results were non-significant. LIMITATIONS: Due to non-significant results among a small sample size and a low rate of NSSI among the NSSID-group, results remain preliminary. CONCLUSIONS: The study provides information on feasibility and methodological challenges such as intervention effects of the diary. NSSI-images may be common among individuals who engage in NSSI; they may capture ambivalent (positive and negative) appraisals of NSSI and thus play a role in NSSI and possibly a disorder such as NSSID. The preoccupation with NSSI (Criterion C of NSSID in DSM-5) may as well be imagery-based. REGISTRATION: The study was retrospectively registered with the DRKS under the number DRKS00011854.