This intra-psychic perspective emphasizes that the cause of paranoid cognitions is inside the head of the people (social perceiver), and dismisses the possibility that paranoid cognition may be related to the social context in which such cognitions are embedded. This point is extremely relevant because when origins of distrust and suspicion (two components of paranoid cognition) are studied many researchers have accentuated the importance of social interaction, particularly when social interaction has gone awry. Even more, a model of trust development pointed out that trust increases or decreases as a function of the cumulative history of interaction between two or more persons.Another relevant difference can be discerned among "pathological and non-pathological forms of trust and distrust". According to Deutsch, the main difference is that non-pathological forms are flexible and responsive to changing circumstances. Pathological forms reflect exaggerated perceptual biases and judgmental predispositions that can arise and perpetuate them, are reflexively caused errors similar to a self-fulfilling prophecy. It has been suggested that a "hierarchy" of paranoia exists, extending from mild social evaluative concerns, through ideas of social reference, to persecutory beliefs concerning mild, moderate, and severe threats. Physical
A paranoid reaction may be caused from a decline in brain circulation as a result of high blood pressure or hardening of the arterial walls.Drug-induced paranoia, associated with cannabis, amphetamines, methamphetamine and similar stimulants has much in common with schizophrenic paranoia; the relationship has been under investigation since 2012. Drug-induced paranoia has a better prognosis than schizophrenic paranoia once the drug has been removed.
In a paper published in 2010, 41 of 42 individuals had some type medical problem in the first days of life, the most common being feeding difficulties. Respiratory difficulty and jaundice are also relatively frequent. ENT
Recurrent otitis media is common, and many patients required the placement of PE tubes. Small ear canals are also fairly common, but not as much as in 18q-. Gastrointestinal
The most common gastrointestinal abnormality is chronic constipation, though gastrointestinal reflux was also common. Endocrine
Growth hormone deficiency is present in about 20% of people with tetrasomy 18p. Neurologic
Hypotonia and/or hypertonia are present in nearly all individuals with tetrasomy 18p. Approximately 25% have a seizure disorder. Growth
Short stature is common, with ~50% being at or below the 25th centile and 20% being at or below the 3rd centile. Microcephaly is present in about 40% of patients. Development
All reported cases of tetrasomy 18p have some degree of intellectual disability. Most individuals score in the moderate range of intellectual disability based on standardized testing. Genetics
Tetrasomy 18p is caused by the presence of an additional isochromosome composed of two copies of the p arm of chromosome 18. This extra chromosome is classified as a small supernumerary marker chromosome that forms de novo in a parents egg or sperm or, in rare cases, is directly inherited from a parent carrier of the intact small supernumerary marker chromosome. It has been reported in both the non-mosaic as well as the mosaic state.