Neurobiological and Genomic Predictors of Relapse in Depression

The goal of this observational study is to test whether the discontinuation of antidepressant medications for patients with depression can be decided after the normalization of biological parameters. The main questions it aims are: 1. When patients with depression treated with antidepressants, does their brain activity also become normal? If so, 2. Then, can we stop the antidepressant treatment and expect minimum repeat of depression? The participants who receive a specific antidepressant treatment will be asked to: * Undergo quantitative electroencephalography (qEEG), * Record Event-related potential (ERP), * Record Sleep EEG * Answer Hamilton Depression Rating Scale question their psychiatrists asked * Give blood sample for genetic analysis * Repeat the above mentioned procedures for at least 3 times during their treatment period. Researchers will compare the results of patients with the results of healthy controls.