Complex sentence: Primary polydipsia includes psychogenic polydipsia, which is caused by mental disorders, most often schizophrenia, although some forms of primary polydipsia are explicitly characterized as nonpsychogenic, such as in patients with autoimmune chronic hepatitis with severely elevated globulin levels.
Split into simpler sentences: Primary polydipsia includes psychogenic polydipsia, which is caused by mental disorders, most often schizophrenia. Some forms of primary polydipsia are explicitly characterized as nonpsychogenic, such as in patients with autoimmune chronic hepatitis with severely elevated globulin levels.