primary delusion
In psychiatry, a delusion that arises without any preceding psychological cause, as opposed to a secondary delusion that can be explained by other mental phenomena.
Primary delusion is one of the important symptoms in the diagnosis of schizophrenia.
Secondary delusion; arises from other mental phenomena such as hallucinations or mood disturbances, whereas 一次妄想 appears without such antecedents.
Compound of 一次 (primary) and 妄想 (delusion), a direct translation of the psychiatric term 'primary delusion'.