Insulin misuse, whether by omission or deliberate insulin overdose, is increasingly recognized as a maladaptive coping strategy linked to body image concerns, diabetes-related distress, and psychiatric comorbidity, further compounding vulnerability.<h4>Case report</h4>A 15-year-old female with type 1 diabetes mellitus, diagnosed at age 11, was admitted to child and adolescent psychiatry following a suicide attempt by insulin overdose delivered via her Tandem X2 Control IQ insulin pump. The gene discussed is INS; the disease is type 1 diabetes mellitus.