Re-examining thought insertion. Semi-structured literature review and conceptual analysis.

Abstract

Thought insertion is commonly regarded as diagnostic of schizophrenia. Little is known of its aetiology or pathophysiology. To examine the definition and application of thought insertion in psychiatric and allied literatures. A semi-structured literature review and conceptual analysis. When 'narrowly' defined, thought insertion is reliably identified but not specific to schizophrenia. There is a range of related phenomena ('alienated', 'influenced', 'made' and 'passivity' thinking), less consistently defined but also not specific to schizophrenia. Whether thought insertion is solely an abnormal belief (or may also be an experience) is open to question. Nevertheless, the symptom has been used to explain schizophrenia, predict dangerousness and advance theories of 'normal' agency. Most applications have been subject to critique. Despite its widespread occurrence and diagnostic application, thought insertion is an ill-understood and under researched symptom of psychosis. Its pathophysiology remains obscure.