BACKGROUNDSuicide remains a significant global public health issue. According to the World Health Organization (WHO), suicide was the third leading cause of mortality among individuals aged 15-29 in 2021, with a total of approximately 726,000 cases reported annually. The etiology of suicide is complex, involving a combination of biological, genetic, and environmental factors, as well as family history, gender, age, personality traits, cultural background, geographic location, medical conditions, mental illnesses, addictions, and psychosocial stressors. Dysregulation of the Hypothalamic Pituitary Adrenal (HPA) axis and the effects of chronic stress play significant roles in the pathophysiology of mood disorders and suicidal behavior.OBJECTIVEThis study aimed to investigate the levels of Neuropeptide Y (NPY), Orexin, Leptin, and Insulin in cerebrospinal fluid (CSF) samples of individuals who died by suicide compared to those who died from non-suicidal causes.METHODThe study examined 35 cases of suicide by hanging and 35 cases of non-suicidal deaths unrelated to head trauma. Levels of NPY, Orexin, Leptin, and Insulin in CSF samples collected during toxicological examinations were compared between suicide and control groups.RESULTSNPY levels were significantly higher in the suicide group than in the control group (p < 0.001). No statistically significant differences were found in Orexin (p = 0.194), Insulin (p = 0.892), or Leptin (p = 0.445) levels between the groups.CONCLUSIONSWhile no definitive biomarkers for diagnosing or predicting suicidal behavior exist, this panel of biomarkers could provide valuable insights for developing targeted treatments to manage patients at risk.