Vortioxetine Monotherapy for Major Depressive Disorder in Type 2 Diabetes

Inclusion Criteria: * Adults 40 to 65 years of age at time of screening visit. * Women only: Must be post-menopausal at time of screening visit (i.e., defined by NO menstruation for at least the past 12-months). * Diagnosis of T2D, as defined by a diagnosis of T2D (for at least 12 months) in the medical record made by a physician (i.e., denoted as 250.XX according to ICD-9/ICD-10 billing codes) OR * current use of oral hypoglycemic medications or insulin OR * having a fasting plasma glucose ≥126 mg/dL in the medical record OR * having a 2-hour oral glucose tolerance test ≥200 mg/dL in the medical record * Patients who meet criteria for current MDD without significant co-morbid psychiatric diagnoses, as determined by study PI from screening visit: * Clinical Psychiatric Interview to determine DSM-V criteria for current MDD AND * A minimum score of 18 on the Hamilton Depression Scale (HAM-D) * Patients with T2D and current MDD that would benefit from antidepressant therapy, which may include: * Patients with current MDD who were NOT prescribed an antidepressant medication in the past; * Patients with current MDD who are NOT responding to their current prescribed antidepressant; * Patients with current MDD who are experiencing breakthrough depressive symptoms despite being maintained on another antidepressant. * Must have the ability to provide informed consent to participate in the study. Exclusion Criteria: * Patients with any form of contraindication to Vortioxetine treatment, as outlined in the medication packet insert, (e.g., presence of a known hypersensitivity to the study drug or hypersensitivity to MAO-I use, etc.). MRI-Related Exclusion Criteria * Participants weighing \>550 lbs (per MRI weight restrictions set by Loyola University Medical Center); * Patients with a pacemaker, AICD, ossicular prosthesis, nerve stimulator, or another contraindication to MRI; * Pregnant patients; * Patients with an inability to tolerate being in enclosed places/spaces such as MRI; * Patients with a history of neurosurgery, brain irradiation, or cerebral endovascular treatment.; * Patients with history of epilepsy, stroke, neurodegenerative disorder, severe traumatic brain injury, hydrocephalus or demyelinating disorder; * Patients with a history of malignant neoplasm Exclusion Criteria to Reduce False Positive Rates of Inflammation * Specific pre-existing chronic pain conditions such as rheumatoid arthritis or fibromyalgia. However, this will NOT include more localized pain-related conditions such as low-back pain or complications associated with T2D (e.g., diabetic neuropathy). * History of peptic ulcer complicated by perforation, hemorrhage, or obstruction; symptoms of peptic ulcer within 4 weeks of enrollment date that has not been treated. * Current diagnosis of substance abuse/dependence during the 6 months prior to study enrollment. * Current diagnosis of uncontrolled hypertension, anemia, liver disease, kidney disease, stroke, and autoimmune disease. Based on the clinical judgment of the study PI, a risk assessment will be conducted if a participant endorses any of these diagnoses but would be otherwise a suitable participant to enroll in the study. * Current acute infection/infectious disease (i.e., a cold or the flu). Based on the clinical judgement of the study PI, a risk assessment will be conducted if a participant endorses some acute infection/infectious disease, but would be otherwise suitable to enroll in the study following a brief wait period for full symptom remission. * Pre- and peri-menopausal women (i.e., defined as the presence of ANY menstruation within the past 12 months). * Certain steroids (e.g., use of hormonal birth control) and any systemic corticosteroids. Please note that hormone replacement therapy will be allowed along with any topical corticosteroid creams. * Patients currently enrolled in any other clinical trial for treatment of MDD (e.g., patients receiving experimental vitamin D supplementation).