Prevention of Lowered Mood in Major Depressive Disorder with Quetiapine extended release after remission has been induced by electroconvulsive therapy (ECT)

There is emerging that the medication, Quetiapine (trade name: Seroquel) is clinically useful in treating clinically significant depression (major depressive disorder) and in the augmentation of antidepressant medication in this condition and depression that occurs in bipolar disorder (manic-depression). Quetiapine is currently approved for the treatment of schizophrenia and bipolar disorder. This study will look at whether the addition of the medication Quetiapine XR (trade name: Seroquel XR) to standard antidepressant medication is better than antidepressant medication alone in keeping symptoms of depression to a minimum after a clinically beneficial course of electroconvulsive therapy (ECT) within the previous 3 weeks for clinical depression (major depressive disorder). Participation in the study will occur after remission (disappearance) of clinically significant depression has occurred after treatment with ECT, when there has been failure to respond to an adequate trial of at least one antidepressant medication, or when ECT is the preferred treatment. People will be invited to participate in the study if they: are aged 18-65 years ;have been diagnosed as experiencing major depressive disorder; have had a course of ECT completed within the previous 3 weeks, which has led to remission of depression sustained over the last 2 ECT treatments of the ECT course, after failure to respond to an adequate trial of at least one antidepressant medication, or when ECT is the preferred treatment. People will not be able to participate in the study if they are: at immediate risk to themselves or others; dependent on alcohol or other substances, apart from caffeine or nicotine; or have diabetes mellitus that is not stable or well controlled. Women who are pregnant, or may become pregnant, or are lactating during the course of the study, will also not be able to participate in the study. There will be 2 groups of 20 participants, each, in the study. One group will be treated with the medication Quetiapine XR in combination with an antidepressant medication. Another group will be treated with an antidepressant medication alone. The antidepressant medications, either a selective serotonin reuptake inhibitors (SSRI) or serotonin and noradrenaline reuptake inhibitor (SNRI) that has not been previously prescribed, or previously not helpful in preventing relapse of clinically significant depression, will be prescribed by treating doctors. The addition of Quetiapine XR to the antidepressant medication will be randomly determined, so that the study doctors or treating doctors will have no prior knowledge nor influence on whether this medication is added to prescribed antidepressant medication. The dose of Quetiapine XR will range from 50 milligrams to a maximum of 300 milligrams per day, with doses adjusted according to clinical response to, and tolerability of this medication. Psychiatric medications other than the prescribed antidepressant medication or Quetiapine XR, will not be prescribed or permitted during the course of the study. The duration of the study is 6 months, with weekly study visits for the first month and monthly, thereafter for the remaining 5 months. Participants will be asked questions about the presence of depressive symptoms and how they are tolerating their medication, as well as a physical examination as part of each study visit. Participants will have blood tests (clinical chemistry, haematology) prior to commencing the study, and at 1,2,3 and 6 months. Participants will also have a fasting (not having eaten, or drunk anything other than water since midnight) prior to commencing the study, and at 3 and 6 months. Participants will also have a urine drug test and electrocardiogram (ECG) prior to commencement. Participants will be free to withdraw their consent at any stage without affecting or prejudicing their clinical care in any way. In the event of depressive relapse (recurrence of clinically significant depression), participants will be discontinued from study, with alternative treatment arrangements made in consultation with their primary treating medical practitioner.