Dual Misuse of Insulin in an Adolescent With Type 1 Diabetes: A Case Report and Management Implications.

Introduction: In Canada, nearly one in five children present with diabetic ketoacidosis (DKA) at the time of their first diabetes diagnosis, a serious and potentially life-threatening complication. Adolescence, marked by insulin resistance, fluctuating appetite, and increasing independence, presents unique challenges for diabetes management. Suicidality is more prevalent in adolescents with type 1 diabetes, with higher rates of ideation and attempts compared to peers without the condition. 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. Case Report: 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. She had a history of multiple suicide attempts, typically in the context of acute psychosocial stressors, and recently transitioned to foster care. Biochemistry revealed suboptimal glycemic control (HbA1c 8.5%) and mild metabolic acidosis. A multidisciplinary review led to targeted insulin adjustments and the introduction of a pump passcode lock, restricting unsupervised bolus dosing as a safeguarding measure against insulin overdose. Psychiatric management was optimized, and coordinated aftercare planning was arranged with child protection, endocrinology, and mental health services. Conclusion: This case illustrates insulin manipulation as a means of self-harm in adolescence. The current admission involved a deliberate insulin overdose with mild DKA in the context of a history of insulin omission and more severe DKA episodes. Few published reports describe such dual misuse, underscoring the need to explicitly assess both behaviors in routine care. In this instance, reintroduction of pump therapy with passcode-protected bolus delivery and tailored alarm configurations provided an additional safeguard, highlighting the potential for diabetes technology, when thoughtfully configured, to augment safety alongside psychiatric and psychosocial intervention.