JMIR Publications

ABSTRACT

Background:

Self-harm, including suicidal thoughts, non-suicidal self-injury (NSSI), and related maladaptive coping behaviors, like disordered eating, are a major public health concern among adolescents and young adults. Youth increasingly encounter self-harm–related content in digital environments, including websites that explicitly encourage harmful behaviors. Although exposure to such content has been linked to poorer mental health, most research is cross-sectional and does not distinguish between one-time and persistent engagement. Whether persistent exposure to these websites represents a distinct digital risk trajectory associated with subsequent mental health outcomes remains unclear.

Objective:

This study examined longitudinal patterns and predictors of exposure to self-harm–encouraging websites over one year and tested whether persistent exposure predicted subsequent suicidal ideation, NSSI, and disordered eating.

Methods:

We analyzed data from 2,197 US youth aged 13–22 years who completed Waves 2 and 4 of Project Lift Up, a national longitudinal cohort study. Website exposure was categorized into four trajectories across one year: none, desist (Wave 2 only), new (Wave 4 only), and persistent (Waves 2 and 4). Logistic regression models estimated associations between exposure trajectory and new Wave 4 suicidal ideation (past 2 weeks), NSSI (past 2 weeks), and disordered eating (past 30 days), restricting analyses to participants without the outcome at Wave 2. Models adjusted for baseline depression/anxiety symptoms, demographic characteristics, and each baseline self-harm indicator. Adjusted predicted probabilities were estimated using post-estimation margins.

Results:

Overall, 26.5% of participants reported exposure to self-harm–encouraging websites during the study period, and 18.5% demonstrated persistent exposure. Intentional motivations for initial exposure (e.g., privacy concerns, embarrassment, curiosity, and lack of offline support) were associated with greater odds of persistent engagement (adjusted odds ratios [aORs] 1.84–3.23), whereas accidental exposure was associated with lower odds of persistence (aOR 0.28, 95% CI 0.19–0.41). Compared with no exposure, persistent exposure was associated with higher odds of suicidal ideation (aOR 1.82, 95% CI 1.20–2.75), NSSI (aOR 3.01, 95% CI 1.98–4.60), and disordered eating (aOR 2.45, 95% CI 1.55–3.86). Adjusted predicted probabilities showed a graded pattern, with persistent exposure associated with the highest risk (suicidal ideation: 32.9% vs 21.6%; NSSI: 25.2% vs 10.3%; disordered eating: 11.9% vs 5.4%). New exposure was associated with increased odds of NSSI (aOR 2.39, 95% CI 1.35–4.22) but was not significantly associated with suicidal ideation or disordered eating. Desisting exposure was not significantly associated with outcomes.

Conclusions:

Persistent engagement with self-harm–encouraging websites represents a distinct digital risk trajectory associated with elevated subsequent risk of suicidal ideation, NSSI, and disordered eating. Assessing persistence and motivation for digital engagement, not merely exposure, may improve identification of youth at heightened clinical risk and inform prevention strategies within digital mental health and clinical settings. Clinical Trial: not applicable