 More than one third of all people admitted to ICUs in hospitals require mechanical ventilation for respiratory failure. Many people who survive after being on mechanical ventilation for a prolonged time have significant issues with recovery and quality of life when discharged from the ICU. They are also more prone to depression, which increases patient suffering and the need for medical care, decreases quality of life, and is associated with increased mortality. Previous research indicates that antidepressant medications may improve quality of life and recovery in people who have had a heart attack, but that behavioral treatments are not effective in this case. Treating depression in ICU patients with respiratory failure has not been examined. In this study, antidepressant medications will be given to people who have been on mechanical ventilation in an ICU to determine the effectiveness of antidepressants in improving medical recovery and quality of life. Only a small number of participants will be enrolled in this trial to test the methods and theory; if it is successful, a larger trial will be conducted to determine whether these findings can be widely generalized. 