There is heterogeneity in patients with depression. Many scholars propose that individualization of antidepressant achieves better outcomes. However, the scientific theoretical basis of individualized treatment is still quite weak. Different clinical subtypes of depression and their possible biomarkers are critically needed to provide the individualization with theoretical base. Diagnostic types of major depression disorder (MDD) based on the Theory of Traditional Chinese Medicine (TCM) and possible differentiations in neurobiochemistry, metabonomics and neuroimaging could be one of ways to explore the biomarkers and support the theory of the individualized treatment. The hypothesized results will be of help to clarify the biological basis of MDD with LDQS and with DBHS, to provide the TCM with further scientific evidence, to explore the pathogenesis of depression, to improve the objective diagnosis of depression, and to promote targeted interventions by Western medicine, TCM or both.

The objectives of this study is to explore if there are any differences in neurobiochemistry, metabonomics and neuroimaging (1) at the baseline, between the subjects who are the normal controls (C Group) and who both meet diagnostic criteria of the Diagnostic and Statistical Manual of 5th edition (DSM-V) on MDD and TCM criteria of 'pattern of Liver Depression and Qi Stagnation (LDQS)' or'pattern of Deficiency of Both Heart and Spleen (DBHS)' (T Group); (2) at the baseline, between the MDD subjects of LDQS and DBHS; (3) after 6-week venlafaxine administration, between the MDD subjects of LDQS and DBHS. 50 subjects in T Group and 25 in C Group are recruited in the study and the main laboratory tests include High Performance Liquid Chromatography(HPLC), Gas Chromatography-Mass Spectrum(GCMS) and neuroimaging DTI technology.