Patient description: A 22-year-old Caucasian man came to the Clinic with a history of tremors since a year ago. The tremor was first in his right hand while holding something. Later the tremor became continuous and extended to both hands and legs and even at rest. The Kayser-Fleischer' ring was detected in the ophthalmologic exam. The physical exam revealed jaundice, hepatosplenomegaly and hypotonia of the upper limbs. He had a constant smile on his face, however, he has aggressive behavior according to his parents' explanation. His laboratory study was significant for a low serum caeruloplasmin (0.05 g/l), and a raised 24 hour urine copper excretion (120 μg/24 h). Wilson disease was confirmed by high liver copper concentration (305 μg/g dry weight of liver).

Clinical trial eligibility criteria: eligible ages (years): 18.0-70.0,  Depressive Disorder, Major -Male and female patients aging 18-70 years, with a DSM-5 diagnosis of MDD who will be commenced on ECT treatment by their treating psychiatrist American Society of Anesthesiologists' (ASA) Physical Status class of I-II Verbal IQ equivalent to 85 or greater and sufficiently fluent in English to validly complete neuropsychological testing Provision of written informed consent before initiation of any study-related procedures Eligible participants who have consented to standard ECT treatment for their mood disorder and are willing to accept randomization to either DEX+ECT or Placebo+ECT Subjects meeting for Major Depressive Disorder (MDD) according to the Diagnostic and Statistical Manual for Mental Disorders (DSM-5) currently in a Major Depressive Episode (MDE) as confirmed by the MINI International Neuropsychiatric Interview (MINI) A Montgomery-Åsberg Depression Rating Scale (MADRS) total score of ≥ 26 at screening and at randomization, with no more than 20% improvement between these two visits Female subjects of childbearing potential must have a negative urine pregnancy test at enrolment (Visit 1) and be willing to use a reliable method of birth control (i.e., double-barrier method, oral contraceptive, implant, dermal contraception, long-term injectable contraceptive, intrauterine device, or tubal ligation) during the study Be able to understand and comply with the requirements of the study, as judged by the investigator(s)  -Prior or current substance abuse or dependence (except for caffeine or nicotine dependence) and/or recent history (last 12 months) of current alcohol abuse or dependence, as defined in DSM-5 ("a problematic pattern of using alcohol or another substance that results in impairment in daily life or noticeable distress") A positive toxicology screen for drugs that are not prescribed and Alcohol Use Disorder Vascular Depression due to stroke, or MDD in the context of cancer diagnoses or other severe medical illnesses( SLE, MS etc) Unwilling to maintain current antidepressant regimen Unwilling to discontinue any narcotic for a minimum of 5 drug half-lives prior to DEX infusion Pregnant, lactating, or of childbearing potential and not willing to use an approved method of contraception during the study Evidence of clinically relevant disease, e.g., uncontrolled hypertension, hypotension, renal or hepatic impairment, significant coronary artery disease (myocardial infarct within a year prior to initial randomization), cerebrovascular disease, cardiac insufficiency, sick sinus syndrome, bradycardia, atrioventricular block of degree II and III, history of cerebrovascular accident, viral hepatitis B or C, acquired immunodeficiency syndrome A clinical finding that is unstable or that, in the opinion of the investigator(s), would be negatively affected by the study medication or that would affect the study medication (e.g., diabetes mellitus, hypertension, unstable angina) Liver function tests AST and ALT three times the upper normal limit at screening Uncorrected hypothyroidism or hyperthyroidism. Subjects needing a thyroid hormone supplement to treat hypothyroidism must have been on a stable dose of the medication for 30 days prior to enrolment (Visit 1)