Help or harm? Assessing positive and unwanted effects of a self-guided internet-based intervention for gambling problems.

Background: Self-guided internet-based interventions have been established as effective tools for reducing gambling disorder. However, research on their potential negative side effects remains limited. This study investigated both unintended positive effects, and unwanted negative effects, of the self-guided internet-based intervention 'Restart' for individuals with self-reported gambling problems. Methods: A total of 94 participants with self-reported gambling problems were investigated for positive and unwanted effects using the Positive and Negative Effects of Psychotherapy Scale for Internet-Based Intervention (PANEPS-I) after using the internet-based intervention 'Restart' for six weeks. Results: The findings indicate that positive effects, such as increased self-efficacy (64.8 %), were reported more frequently than unwanted effects. Nonetheless, a significant proportion of participants experienced side effects (23.9 %), alleged malpractice (38.6 %), and found procedures unethical (21.5 %). Key unwanted effects included feelings of stigmatization and blaming, experiences of excessive pressure during the intervention and perceptions of the program as overly directive or as not in line with own preferences. Positive effects but not unwanted effects significantly increased the likelihood for a positive response (Odds ratio = 1.59 Conclusion: The findings suggest that while self-guided internet-based interventions can serve as valuable tools for individuals reluctant to seek traditional therapy, they require careful refinement to address user-specific needs and reduce adverse outcomes. Future research should focus on identifying factors that predispose individuals to positive and unwanted effects and explore intervention modifications, such as integrating optional therapeutic support or personalized content adaptations.