A number of studies have suggested that subtle behavioral or personality changes may occur in infected humans,[19] and infection with the parasite has recently been associated with a number of neurological disorders, particularly schizophrenia.[13] A 2015 study also found cognitive deficits in adults to be associated with joint infection by both T. gondii and Helicobacter pylori in a regression model with controls for race-ethnicity and educational attainment.[20] However, although a causal relationship between latent toxoplasmosis with these neurological phenomena has not yet been established,[6][13] preliminary evidence suggests that T. gondii infection can induce some of the same alterations in the human brain as those observed in mice.