Blood Peptide Nesfatin-1 Flags Self-Harm in Depressed Teens, Study Finds

A single hormone-like molecule measured in a routine blood sample may help clinicians identify which teenagers with depression are carrying a hidden burden of self-harm, according to a new cross-sectional study published in BMC Psychiatry. The molecule, a small peptide called nesfatin-1, is best known for its role in regulating appetite, but a growing body of research has implicated it in stress, anxiety, and mood disorders. In the new work, a team of child and adolescent psychiatrists and biochemists at Giresun University in Turkey reports that adolescents with major depressive disorder who engage in non-suicidal self-injury, or NSSI, have significantly higher circulating levels of nesfatin-1 than depressed adolescents who do not self-harm, even when their depressive symptoms are equally severe. The finding, if replicated, could point toward an objective biological marker for a behavior that is currently detected almost entirely through clinical interviews and self-report.

Non-suicidal self-injury is defined as the deliberate, repetitive destruction of body tissue, such as cutting, burning, or hitting oneself, without any intent to die. It is distressingly common in adolescence, and it frequently co-occurs with depressive disorders, where it can be difficult to distinguish from the emotional turmoil of the illness itself. Because young people often conceal self-injurious behavior out of shame or fear of parental reaction, clinicians rely heavily on screening instruments and careful questioning, and the behavior can go unnoticed until it escalates. The researchers behind the new study set out to ask whether the biology of depression with self-injury might differ measurably from the biology of depression alone, and whether a blood-borne signal could capture that difference.

Their candidate was nesfatin-1, an 82-amino-acid peptide derived from a larger precursor protein called nucleobindin-2, or NUCB2. First identified about two decades ago in the hypothalamus, the brain region that coordinates hunger, satiety, and the body’s stress response, nesfatin-1 powerfully suppresses food intake, which is why it is described as anorexigenic. But the peptide is not confined to feeding circuits. It is expressed in brain areas governing emotion and autonomic regulation, it interacts with the hypothalamic-pituitary-adrenal axis, the central stress machinery of the body, and it appears to modulate endogenous opioid and corticotropin-releasing hormone systems, both of which have been linked to emotional pain and self-harm. Elevated nesfatin-1 has previously been reported in panic disorder, generalized anxiety, and major depression, making it a plausible player in stress-related psychopathology.

To test the hypothesis, the team enrolled three groups of adolescents aged 12 to 18. The first comprised 40 young people diagnosed with major depressive disorder, the second comprised 41 adolescents with major depressive disorder and comorbid non-suicidal self-injury, and the third comprised 45 healthy controls. Crucially, all participants had been free of psychiatric medication for at least eight weeks before enrollment, removing a common confound in biomarker studies, since many antidepressants and other drugs can alter peptide levels. Diagnoses were established with the Schedule for Affective Disorders and Schizophrenia for School-Age Children, Present and Lifetime Version, a structured interview considered a gold standard in child psychiatry research. Depressive symptom severity was quantified with the Children’s Depression Inventory, while self-injurious behaviors were assessed with the Inventory of Statements About Self-Injury, an instrument designed specifically to characterize NSSI.

Serum nesfatin-1 concentrations were measured using a sandwich enzyme-linked immunosorbent assay, a laboratory technique in which antibodies capture the peptide from a blood sample and a second detection antibody generates a measurable signal proportional to the amount present. The results were striking. Nesfatin-1 levels differed significantly across the three groups, with the highest concentrations found in the adolescents who had both depression and self-injury. Both patient groups showed significantly higher levels than the healthy controls, but the self-injuring group also exceeded the non-self-injuring depressed group, a difference that reached statistical significance at p equals 0.010. What makes this particularly notable is that the two patient groups were clinically comparable: their Children’s Depression Inventory scores did not differ significantly, even though both were substantially higher than those of controls.

In other words, nesfatin-1 appeared to track something beyond the severity of depressive symptoms. Across the participants, serum levels correlated positively and strongly with depressive symptom severity, with a Spearman correlation coefficient of 0.691 and a p value below 0.001, indicating that the peptide rises with the depth of the depression. Yet when the researchers compared two groups of equally depressed adolescents, the presence of self-injury was associated with an additional elevation in the peptide. This pattern suggests that nesfatin-1 may reflect neurobiological processes tied specifically to self-injurious behavior, rather than simply serving as a proxy for how depressed a teenager feels on a questionnaire.

The team also examined how well the biomarker performed as a diagnostic discriminator using receiver operating characteristic, or ROC, curve analysis, a statistical method that plots sensitivity against specificity across all possible cutoff values and summarizes the result as the area under the curve, or AUC. An AUC of 1.0 indicates perfect discrimination, while 0.5 indicates performance no better than chance. Nesfatin-1 showed good discriminative ability for separating both patient groups from healthy controls. For the more demanding task of distinguishing adolescents with depression and self-injury from those with depression alone, performance was fair, with an AUC of 0.671 and a 95 percent confidence interval of 0.553 to 0.789, and a p value of 0.008. That is far from a definitive clinical test, but it is a meaningful signal for a single circulating molecule in a behavior as complex as self-harm.

Why might a satiety peptide be elevated in teenagers who hurt themselves? The authors point to nesfatin-1’s extensive connections with the body’s stress systems. The peptide interacts with corticotropin-releasing hormone signaling and with the endogenous opioid system, both of which are deeply involved in how the brain processes emotional distress. Self-injury is often described by those who engage in it as a way of regulating unbearable emotional states, and dysregulation of stress and pain-modulating circuits is thought to underlie that coping mechanism. Elevated nesfatin-1 could plausibly mark a state of heightened stress-system activation in which self-harm becomes more likely, although the cross-sectional design of the study means the direction of the relationship cannot be determined. It remains possible that the behavior itself, or the chronic distress surrounding it, drives peptide levels upward rather than the other way around.

The study’s limitations are those typical of pioneering biomarker work. The sample, while carefully characterized, is modest in size, and the cross-sectional design captures a single moment in time rather than tracking how nesfatin-1 changes as adolescents recover, relapse, or begin or stop self-injuring. The researchers themselves emphasize that future longitudinal studies with larger samples are needed to clarify the role and clinical relevance of the peptide in adolescents with depression and self-injury. Body mass index and metabolic factors, which can influence nesfatin-1 because of its appetite-related functions, are additional variables that larger studies will need to control more exhaustively. No one should expect a nesfatin-1 blood test in the clinic tomorrow.

Nevertheless, the findings add to a growing appreciation that self-injurious behavior in adolescent depression has measurable biological correlates, and they identify a candidate marker that is inexpensive to measure with standard laboratory equipment. If longitudinal research confirms that nesfatin-1 rises before or alongside the onset of self-harm, it could eventually help clinicians flag high-risk patients earlier, complementing psychological screening with an objective physiological signal. For now, the study offers something scientifically valuable in its own right: evidence that the boundary between metabolism and mood runs through molecules like nesfatin-1, and that the hypothalamus, that small cluster of neurons at the base of the brain, may hold clues to one of the most painful and hidden behaviors of adolescence. The research was funded by the Giresun University Scientific Research Projects Coordination Unit and conducted with ethics approval and informed consent from participants and their guardians.

Subject of Research: Serum nesfatin-1 levels as a biomarker associated with non-suicidal self-injury in adolescents with major depressive disorder

Article Title: Nesfatin-1 levels and non-suicidal self-injury in adolescents with major depressive disorder: a cross-sectional study

Article References: Onal, B. S., Arslan, H. F., Cobanoglu Osmanlı, C., Sahin, B., & Yitik Tonkaz, G. (2026). Nesfatin-1 levels and non-suicidal self-injury in adolescents with major depressive disorder: a cross-sectional study. BMC Psychiatry. https://doi.org/10.1186/s12888-026-08612-x

Image Credits: AI Generated

DOI: 10.1186/s12888-026-08612-x

Keywords: nesfatin-1, non-suicidal self-injury, major depressive disorder, adolescents, biomarker, BMC Psychiatry, hypothalamus, stress response, ELISA, ROC analysis, child and adolescent psychiatry, neurobiology