Patient description: A 46-year-old Asian woman with MDD complains of persistent feelings of sadness and loss of interest in daily activities. She states that her mood is still depressed most of the days. She complains of loss of energy and feelings of worthlessness nearly every day. She is on anti-depressants for the past 6 months, but the symptoms are still present. She does not drink alcohol or smoke. She used to exercise every day for at least 30 min., but she doesn't have enough energy to do so for the past 3 weeks. She also has some digestive issues recently. She is married and has 4 children. She is menopausal. Her husband was diagnosed with colon cancer a year ago and is undergoing chemotherapy. Her past medical history is unremarkable. Her family history is negative for any psychologic problems. Her HAM-D score is 20.

Clinical trial eligibility criteria: eligible ages (years): 5.0-84.0,  Smoke Inhalation Injury Burns Child is at least 5 years of age and has not yet had his/her thirteenth birthday (for Studies # 1, 2, and 5) Subject (and child's caretaker for Studies #1, 2, and 5) speak English (2000 Census data indicate that less than 5% of the population older than five years of age in Franklin County, Ohio [where the study is located] speaks English less than "very well") Subject/family is able to be contacted by telephone (to obtain pre-study information and to remind the family about the study appointment and confirm that the child is in a normal state of health on day of study) For adult study arms: Study 3: Subjects are 20-49 years of age; Study 4: Subjects are 60-84 years of age  Subject has a clinical diagnosis that may affect sleep, arousal or ability to perform the escape procedure Subject has a hearing impairment Subject is taking medication that may affect sleep, arousal, or ability to perform the escape procedure Subject has an acute illness at the time of the sleep study. The target population for Study 3 consists of adults 20-49 years of age, who have not yet had his/her fiftieth birthday. Adult participants must not have a clinical diagnosis that may affect sleep, arousal or ability to perform the simulated escape procedure. He/she must not have a hearing impairment; not be taking medication that may affect sleep, arousal, or ability to perform the escape procedure; and not have an acute illness at the time of the sleep study. The adult must speak English and be able to be contacted by telephone (to obtain pre-study information and to remind the participant about the study appointment and confirm that he/she is in a normal state of health on the day of the study). The target population for Study 4 consists of older adults 60-84 years of age, who have not yet had his/her eighty-fifth birthday. The older adult must not have a clinical diagnosis that may affect sleep, arousal or ability to perform the escape; not have a hearing impairment; and not be taking medication that may affect sleep, arousal, or ability to perform the simulated escape procedure. The older adult must not have an acute illness at the time of the sleep study. The older adult must speak English and be able to be contacted by telephone (to obtain pre-study information and to remind the participant about the study appointment and confirm that he/she is in a normal state of health on the day of the study). The target population for Study 5 is the same as that for Studies 1 and 2