This idea however generated much skepticism during its time. Employed as an adjective, paranoid has become attached to a diverse set of presentations, from paranoid schizophrenia, through paranoid depression, to paranoid personality—not to mention a motley collection of paranoid 'psychoses', 'reactions', and 'states'—and this is to restrict discussion to functional disorders.
Even when abbreviated down to the prefix para-, the term crops up causing trouble as the contentious but stubbornly persistent concept of paraphrenia".
A paranoid person may view someone else's accidental behavior as though it is with intent or threatening.
An investigation of a non-clinical paranoid population found that feeling powerless and depressed, isolating oneself, and relinquishing activities are characteristics that could be associated with those exhibiting more frequent paranoia.
Based on data obtained by the Dutch NEMISIS project in 2005, there was an association between impaired hearing and the onset of symptoms of psychosis, which was based on a five-year follow up.
Some older studies have actually declared that a state of paranoia can be produced in patients that were under a hypnotic state of deafness. Mc Kenna, "As a noun, paranoia denotes a disorder which has been argued in and out of existence, and whose clinical features, course, boundaries, and virtually every other aspect of which is controversial.
Drug-induced paranoia has a better prognosis than schizophrenic paranoia once the drug has been removed.
Making false accusations and the general distrust of other people also frequently accompany paranoia.
Due to the suspicious and troublesome personality traits of paranoia, it is unlikely that someone with paranoia will thrive in interpersonal relationships.
Most commonly paranoid individuals tend to be of a single status.
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.
Drug-induced paranoia, associated with amphetamines, methamphetamine and similar stimulants has much in common with schizophrenic paranoia; the relationship has been under investigation since 2012.
According to some research there is a hierarchy for paranoia.