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): 45.0-75.0,  Colorectal Adenoma Colorectal Polyp Colorectal Adenocarcinoma Colorectal SSA Primary Criteria. 1. Average risk asymptomatic subjects undergoing a first colonoscopy (screening) or screening colonoscopy at least 10 years after prior colonoscopy. 2. Aged 45 years to aged 75 years at the time of enrollment. 3. Capable of providing written informed consent and willing and able to adhere to all protocol requirements, and/or the subject's legally acceptable representative(s) capable of providing written informed consent. Primary   1. History of any colorectal cancer or colon adenomas. 2. History of inflammatory bowel disease, including Crohn's disease or ulcerative colitis. 3. Family history of colon cancer or precancerous colon polyp in a first degree relative before age 50. 4. Polyposis syndromes including Familial Adenomatous Polyposis, Cowden syndrome, Lynch syndrome, Peutz-Jeghers syndrome, MUTYH Associated Polyposis, Familial Colorectal Cancer Type X. 5. Surveillance, therapeutic, preoperative, or diagnostic colonoscopy. 6. Colonoscopy for work-up of abdominal or pelvic symptoms including abdominal pain, flank pain, pelvic pain, subject report of altered stool, subject report of anemia within the past 12 months, subject report of gastrointestinal bleeding including bright red blood per rectum or tarry stools, constipation, diarrhea, subject reported history of abdominal or pelvic mass, subject report of unintentional weight loss. 7. Workup or referral to diagnose or evaluate abnormal imaging of the abdomen or pelvis. 8. Positive Fecal Immunochemical Test history. 9. Severe co-mobordity, including end-stage cardiovascular, pulmonary, liver, or renal disease. 10. History of colon resection, not including the appendix. 11. Currently receiving a therapy not permitted during the trial, as defined in Section 8.3. 12. Any issue that, in the opinion of the investigator, would render the subject unsuitable for participation in the trial. Enrolled subjects will be eligible for Post-procedure Periods if their colonoscopy meets the following 1. Adequate bowel preparation score per the Boston Bowel Preparation Scoring System (BBPS) > or equal to 2 in all colonic segments. 2. Colonoscopies with successful cecal intubation. 3. Colonoscopies with withdrawal times of at least 6 minutes