Introduction: Toxoplasma gondii is an intracellular parasite that affects about one third of the population in developed countries. It is known that in the brain and muscle tissues of infected people, this parasite maintains its stagnant phase lifelong. T. gondii relation, in terms of neurotropism is shown up to 60% in anxiety, depression, even schizophrenic psychoses. Schizophrenia and bipolar affective disorder (BAD) are neuropsychiatric disorders seen worldwide and their etiologies are not fully understood. Recently, it is suggested that although it is clinically indefinite, it may be a neurotropic agent, such as the trophozoites of the parasite, that have a special affinity to the glia cells of the brain.