<unk>  is a mental disorder characterized by an organized system of paranoid delusions with or without hallucinations (the positive symptoms of schizophrenia) and without deterioration of intellect or personality (its negative symptom). This disorder is also distinguished from schizophrenia by a lower hereditary occurrence, less premorbid maladjustment, and a slower rate of progression. Onset of symptoms generally occurs later in life, near the age of 60. The prevalence of the disorder among the elderly is between 0.1% and 4%.<unk>  is not included in the DSM-5; psychiatrists often diagnose patients presenting with<unk>  as having atypical psychoses, delusional disorder, psychoses not otherwise specified, schizoaffective disorders, and persistent persecutory states of older adults. Recently, mental health professionals have also been classifying<unk>  as very late-onset schizophrenia-like psychosis. In the Russian psychiatric manuals,<unk>  (or<unk>  syndrome) is the last stage of development of paranoid schizophrenia. "Systematized<unk> " (with systematized delusions i. e. delusions with complex logical structure) and "expansive-paranoid<unk> " (with expansive/grandiose delusions and persecutory delusions) are the variants of paranoid schizophrenia (). Sometimes systematized<unk>  can be seen with delusional disorder (). The word is from – beside, near + φρήν – intellect, mind.
Paraphrenia
Oneirophrenia
Hapalonychia
Amastia
Dolichonychia
Steatopygia
White piedra
Platonychia