Ischemic Stroke precedes depression . Post Stroke Depression (PSD) is a major driver for poor recovery, negative quality of life, poor rehabilitation outcomes and poor functional ability. This systematic reviews confirmed the post stroke depression as the norm as complex ischemic cascade involve the bioenergetic failure, deranged iron homeostasis ( calcium influx, Na influx, potassium efflux etc) excitotoxicity, acidotoxicity,disruption of the blood brain barrier, cytokine mediated cytotoxicity, reactive oxygen mediated toxicity , activation of cyclooxygenase pathway and generation of toxic products, infiltration of immune mediated cells resulting the cell death and deranged neuronal networks in mood related brain regions. This review focus on the pathobiology of stroke in the context and make the argument that PSD is the norm after a stroke rather than the exception.