Algorithm Guided Treatment Strategies for Major Depressive Disorder

The AGT arm includes a 2-step medication monotherapy and a combination treatment algorithm. The first step (level 1) includes two medication monotherapy options: escitalopram and mirtazapine. For those participants who don't remit with the initial intervention after up to 6 to 12-week treatment, the second step (level 2) with a variety of treatment options will be provided. In level 2 intervention, a switch strategy for those who don't remit with escitalopram will be switched to mirtazapine, or for those who don't remit with mirtazapine will be switched to escitalopram, combination strategy (i.e. escitalopram plus mirtazapine) and augmentation strategy (i.e. escitalopram or mirtazapine plus either rTMS or mECT). Participants who don't get remission in level 1 intervention will be encouraged to enter level 2 interventions based on intend-to-treatment principle. The TAU arm as control intervention is performed using the psychiatrist's individual discretion based on his/her expertise and knowledge. Participants will be recruited consecutively in 8 psychiatric settings across China and randomized into any of the two initial interventions of AGT or TAU arm. Follow-up interviews will be performed monthly for all participants who finish any acute treatment of AGT or TAU. The follow-up period will last up to 6 months.