What diagnosis is most likely for an 11-year-old boy showing symptoms of irritability, decreased interest in activities, and thoughts of suicide?

The key symptoms presented by this 11-year-old boy—irritability, decreased interest in activities, and thoughts of suicide—align closely with the criteria for Major Depressive Disorder (MDD).

Major Depressive Disorder in children and adolescents can manifest with irritability rather than the classic presentation of sadness or hopelessness seen in adults. Additionally, decreased interest in previously enjoyed activities and thoughts of suicide are significant indicators of MDD. This disorder generally includes a range of emotional and functional impairments, pointing to the serious nature of the child's mental health.

While other conditions like Attention-Deficit/Hyperactivity Disorder might involve irritability, they typically do not include profound mood changes or suicidal thoughts as a primary symptom. Persistent Depressive Disorder (Dysthymia) is characterized by longer-lasting depressive symptoms but generally does not present with the intensity of symptoms or the acute suicidal ideation seen in MDD. Schizophrenia, while a serious mental health disorder, would typically present with psychotic symptoms rather than purely depressive symptoms and is less common in this age group without preceding indicators.

Therefore, the combination of the specific symptoms—irritability, anhedonia, and suicidal thoughts—strongly suggest that Major Depressive Disorder is the