behavior, disturbed thoughts, emotions, and relationships with others. They are considered the
3rd most common diseases worldwide, after malignancy and cardiovascular diseases, but the
etiology of psychiatric disorders is still questionable. Besides, biological, psychological, and
environmental factors increased evidence for the role of viral, bacterial, and parasitic infections
in the development of some psychiatric disorders. Studies suggested an association between
parasites, especially those with neurological tropism and psychiatric disorders. Toxoplasmosis,
human African trypanosomiasis, malaria, Chagas' disease, neurocysticercosis, and human
toxocariasis are neurotropic parasitosis that has a predilection for central nervous system in different
ways, which could be a trigger to develop neuropsychiatric disorders. Neurological and
psychiatric sequelae of these infections result mainly from a complex interplay between parasite
and host inflammatory and immune response affecting insitu brain neurotransmitters or causing
vascular impairment and some work as space occupying lesions. The study reviewed how
those neurotropic parasites could be etiological agents for psychiatric and mental disorders.