Radhika J. Kothadia, MD PGY-3 General Psychiatry Resident Prisma Health/University of South Carolina School of Medicine Columbia, South Carolina
Kaustubh G. Joshi, MD Associate Professor of Clinical Psychiatry Associate Program Director, Forensic Psychiatry Fellowship Department of Neuropsychiatry and Behavioral Science University of South Carolina School of Medicine Columbia, South Carolina
Richard L. Frierson, MD Alexander G. Donald Professor of Clinical Psychiatry Vice Chair for Academic Affairs Program Director, Forensic Psychiatry Fellowship Department of Neuropsychiatry and Behavioral Science University of South Carolina School of Medicine Columbia, South Carolina
Disclosures The authors report no financial relationships with any companies whose products are mentioned in this article, or with manufacturers of competing products.
Though less robust than data published regarding adolescents, the role of biological processes in adults engaging in NSSI has also been studied. A 2021 study by Störkel et al49 found that levels of salivary beta-endorphins were significantly lower in adults immediately before engaging in NSSI compared to after NSSI. Furthermore, adults who engage in NSSI have lower levels of met-enkephalin (P < .01), an opioid growth factor, compared to adults who have never engaged in NSSI.22
Dynamic risk factors
Individuals who engage in NSSI often report substance use, but there is little data on whether substance use is an independent risk factor for NSSI. Although limited, recent evidence suggests illicit substance use in both adolescents41 and adults50 increases risk for NSSI. Richardson et al50 found that the use of barbiturates, opiates, and sedatives significantly increased the frequency of NSSI, whereas use of marijuana, phencyclidine, and medications used to treat anxiety significantly increased the severity of NSSI. A smaller study conducted in South Africa found that individuals who engage in substance use and NSSI were more likely to be male (P < .001).51
Eating disorders and NSSI are highly comorbid.52 The lifetime prevalence of NSSI among individuals with eating disorders ranges from 20.6%to 37.1%.52,53 Results are inconsistent regarding which eating disorders (if any) are greater risk factors for NSSI. One study found that the prevalence of NSSI in patients with bulimia nervosa was 32.7% (95% CI, 26.9% to 39.1%) vs 21.8% in patients with anorexia nervosa (95% CI, 18.5% to 25.6%).54 Another study found that individuals with binge eating/purging–type eating disorders reported engaging in NSSI more frequently than those with other types of eating disorders.55 Among patients with eating disorders who reported NSSI,risk factors included younger age of onset, more negative self-evaluation, more impulsive behavior, concomitant substance use, history of suicide attempts, childhood abuse, and peer aggression.53,55 Body image dissatisfaction and self-criticism, even in individuals not formally diagnosed with an eating disorder, are small but significant predictors of NSSI.56,57
Mood disorders have also been linked to NSSI.58,59 Anxiety disorders (including generalized anxiety disorder, social phobia, panic disorder, and agoraphobia) as well as anxiety-related disorders such as obsessive-compulsive disorder have been significantly associated with NSSI (P < .001), but this relationship decreased in strength when mood instability was removed as a confounder.58 Among patients with anxiety and anxiety-related disorders, panic disorder and posttraumatic stress disorder (PTSD) have shown the strongest association with NSSI, with pooled aORs of 2.67 and 2.06, respectively.59
Recent studies have examined the association of other mental health disorders and symptoms with NSSI, including psychosis60 and dissociative symptoms.61 One study found that paranoia, thought control, and auditory hallucinations were significantly associated with NSSI60; however, after controlling for concomitant BPD, only paranoia was significantly associated with NSSI.60 Individuals diagnosed with dissociative disorders were more likely than patients without such disorders to endorse NSSI and suicide attempts.61
