Assess patients with major depression or substance abuse for suicide ideation, as they are at elevated risk for self-harm. Severity of suicide ideation is associated with suicide risk. Its assessment, therefore, should proceed sequentially from passive to active suicide ideation, to a specific detailed plan, including intention to harm oneself, reasons for living, and impulse control. Primary care patients at mild to moderate risk for suicide can be effectively treated in primary care settings; however, patients at high risk should be referred to mental health specialists given their need for intensive treatments and frequent monitoring.