A Prediction Study of Multiple Indexes of the Effect of Different Mechanisms of Antidepressants Treatment on Depression

Antidepressants is the primary treatment for depression, but only less than 50% of the patients get clinical remission. There is no objective markers to select antidepressants for clinical treatment . Clinical choose usually use experience and waste a lot of time, even the patients cannot be treated timely and effectively. The investigators found that the later antidepressant effect for 8 weeks is related with early brain functional response. Present prospectively drug treatment and follow-up study intends to adopt pharmacological imaging research methods to detect the brain function or structure change of three different mechanisms of antidepressant drugs, selective serotonin reuptake inhibitors (SSRIs, escitalopram), serotonin and norepinephrine reuptake inhibitors (SNRIs, duloxetine), norepinephrine and dopamine reuptake inhibitors (NDRIs, bupropion) in depression patients. Brain functional or structural magnetic resonance imaging data were collected at baseline, 1 days, 14 days and 12 weeks after treatment. The investigators want to observe the changes of brain functional networks and structure at different time points, acute and chronic treatment induced during drug treatment. Combined with the blood concentration detection, symptom change, cognitive function tests, the investigators also hope to determine the different mechanisms of drug efficacy of antidepressants with different mechanisms. The second aim is to explore different mechanisms of brain function for effective or ineffective drug response. The results of the study will help to further explain the mechanism of different antidepressants, to facilitate the development of early indicators for drug efficacy and individual treatment decision.

about 150 depression patients were divided into three subgroups, for each group was treated by one antidepressant eg.escitalopram,duloxetine,bupropion.Brain magnetic resonance imaging data were conducted for all patients at baseline, 1 days, 14 days and 12 weeks after treatment. The blood concentration detection, symptom change, cognitive function tests were also conducted. combined with these results the investigators aim to determine the different mechanisms of drug efficacy of antidepressants with different mechanisms and to explore different mechanisms of brain function for effective or ineffective drug response

Eligibility Criteria:
Inclusion Criteria:

* Diagnostic and Statistical Manual (DSM)-IV Major Depression or Dysthymia
* Age 18-60
* Physically healthy
* The score of Hamilton Depression Rating Scale (HAMD)≥18 points
* Drug-free

Exclusion Criteria:

* Body metal (e.g., wire stitches, screws in bones, stainless steel hips)
* History of Psychosis or Epilepsy
* Current (past six months) Substance Use Disorder (illicit drugs and/or alcohol)
* Bipolar I
* Need for wash-out from effective treatment in order to participate
* Pregnant or breastfeeding
* High suicide risk
* Currently taking (within 2 weeks; 4 weeks for Fluoxetine) antidepressants
* have received regular treatment of electric convulsions, repetitive transcranial magnetic stimulation (rTMS), or systematic psychotherapy within three months