Abstract
OBJECTIVE: Understanding of nonsuicidal self-injury relies almost exclusively on adolescent and emerging adult samples. We investigated the prevalence of lifetime and past-year nonsuicidal self-injury among New Zealanders aged 16-75 years and above, before evaluating if established associations between nonsuicidal self-injury, and demographic and psychological characteristics generalise to adults. METHOD: New Zealand adults (n = 4906; median age 55-59 years; 55.5% female) completed a cross-sectional survey assessing lifetime and past-year nonsuicidal self-injury, psychological distress, self-esteem, emotion dysregulation, and social desirability susceptibility. RESULTS: Nonsuicidal self-injury was common among adults; 25.6% participants reported ever self-injuring and 10.7% had done so at least once in the past year. Women and younger participants were more likely to report lifetime self-injury. Although younger participants were also more likely to report past-year self-injury than older participants, this age effect was attenuated for men (b = -0.09) compared to women (b = -0.18). Self-esteem (odds ratios 0.74, 0.74), psychological distress (odds ratios 1.09, 1.16), emotion dysregulation (odds ratios 2.05, 1.88), and desire to manage others' impressions of oneself (odds ratios 0.88, 0.85) were uniquely associated with both lifetime and past-year nonsuicidal self-injury, respectively, and these effects were not moderated by age. CONCLUSION: Although self-injury was most common among emerging adults, adults of all ages reported self-injuring. Individuals with a greater desire to manage how others perceive them appeared to underreport their nonsuicidal self-injury. While men were less likely than women to self-injure, they may also be more likely to continue self-injuring over adulthood, suggesting that the developmental factors which drive self-injury cessation among adults differ for men and women.