Progress in areas of research from the field of G Protein Coupled Receptor (GPCR) signalling, now shows that GPCRs are involved in a broad range of cellular regulatory activities. By virtue of widespread distribution and important roles in cell physiology and biochemistry, GPCRs play multiple important roles in clinical medicine. The understanding of how the GPCR interact (G proteins and effectors, as well as other regulatory proteins) thus has enormous implications for clinical medicine. The rapid progress in determining three-dimensional structures of GPCRs and more recently their regulators and effectors, has illuminated the search for mechanisms of activation and regulation and has allowed structure-based mutagenesis to test these ideas. The structural and mechanistic studies will in the future also hopefully provide opportunities to alter those interactions in pathological situations. A compilation of the most relevant research topics about the implication of heterotrimeric G proteins in the etiology of genetics and neurobiology of mood will provide a broad perspective of this potential therapeutic target field. In this review, we tried to show how far GPCR research involved in recent medicine.