Thought Insertion

Much of the information on this page comes from Mullins and Spence (2003). The web-link can be found at the bottom of this page.

Thought insertion is a symptom of psychosis and not specific to schizophrenia, although it occurs in approximately a fifth of patients with schizophrenia, (Mullins and Spence 2003). It includes the delusional belief that the mind or “ego” has been intruded upon and that thoughts have been inserted from external sources, i.e. the person feels that certain thoughts that they are experiencing ..

  • do not belong to them
  • they do not accept responsibility for having created them
  • these thoughts originated in the minds of others, yet have been implanted in their minds.
  • the thoughts are alien to them

‘The subject believes that thoughts that are not his own have been inserted into his mind.’ (Andreasen, 1984)

The subject ‘experiences thoughts which are not his own intruding into his mind. The symptom is not that he has been caused to have unusual thoughts, but that the thoughts themselves are not his’ (Wing et al, 1983).

Sometimes the person may report that they “feel” thoughts actually coming into their minds, e.g. Cahill & Frith (1996) describe a patient who identified the exact point of entry of an inserted thought into his head.


‘I look out of the window and I think the garden looks nice and the grass looks cool, but the thoughts of Eamonn Andrews come into my mind. There are no other thoughts there, only his…He treats my mind like a screen and flashes his thoughts on to it like you flash a picture’. (Mellor, 1970)

Thoughts ‘come at any moment like a gift…I do not dare to impart them as if they were my own’ (Jaspers, 1963).

‘Patients think something and yet feel that someone else has thought it and in some way forced it on them. The thought arises and with it a direct awareness that it is not the patient but some external agent that thinks it. The patient does not know why he has this thought nor did he intend to have it. He does not feel master of his own thoughts and in addition he feels in the power of some incomprehensible external force’ (Jaspers, 1963, pp. 122-123).

Other similar but DIFFERENT symptoms:Influenced thinking” The patient’s OWN thoughts are being controlled or influenced by an outside force’ (Koehler, 1979), e.g. he or she accepts that the thoughts have originated in their own mind, they belong to him or her, but believes that their thoughts are being controlled externally by someone else.

Links to auditory hallucinations (hearing voices):  Hearing voices is another common symptoms of schizophrenia however in this case the person actually reports hearing voices which they perceive as outside of their own head/mind. With thought insertion the person is aware of thoughts inside their head/mind like an “internal hallucination” but believe that the thoughts don’t belong to them. Sometimes the “thoughts” appear to the “mind’s eye” rather than to the “mind’s ear”  as unpleasant visual images (e.g. to maim or kill).

Thought insertion and “ego-boundaries”: Sims (1991) describes each person as having an “ego-boundary” or a psychological border, between “me” and “not me” however for people experiencing psychosis, that border may seem as though it  has become “permeable”, meaning that thoughts/feelings/experiences can pass through from one person to another. When thought insertion occurs, there has been a “subjective breach of a perceived psychological border” (Mullins and Spence (2003) whereby thoughts that have been created by someone else, originating from their mind, are perceived to have crossed the ego boundary into the other person. Other related symptoms include “thought withdrawal” and “thought broadcasting” whereby the person feels that their thoughts are accessible to others or that they have left their mind and are therefore able to be experienced by others, e..g one patient explained that her thoughts were able to ‘fly’ to others, who could ‘catch’ them.

Links to the 4 Ds and the validity of diagnosis: 

Deviance, dysfunction and distress:: Thought insertion is an example of a delusional belief although it is also sometimes a feeling/experience as well. However, a belief is not regarded as delusional if it is in-keeping with the social and cultural norms to which that person has exposed, (i.e. there is no deviance from social norms). Mullins and Spence (2003) say that “certain phenomena resembling thought insertion have gained cultural credence through being incorporated into occult, para-psychological and religious literature. Similar beliefs are also contained in certain religious writings, e.g. the Christian New Testament, Mark 13:11 describes an inspired external control, affecting thought and speech”. Psychiatrists must take care to fully understand a person’s spiritual/religious and cultural background. For example, in a famous case “Simon” described feeling that household appliances were interfering with his thinking, (Jackson & Fulford, 1997) but he was functioning well in every other respect well and is professionally successful (No dysfunction or distress). Due to his religious beliefs his experience of thought insertion was not seen as a symptom of psychosis.

Danger: Mullins and Spence also indicate that thought insertion may be useful in predicting dangerousness. A study by Link et al (1992) showed a possible relationship between violence and experience of symptoms including persecutory delusions and thought insertion, although other studies have suggested that Link’s conclusions may not be valid due to a variety of methodological problems including failure to control for anger and impulsivity, (Appelbaum et al, 2000).

Stretch and Challenge: A useful reference:

Assessment Questions:

  1. Describe one symptom of schizophrenia with reference to one example (3)  (answer on thought insertion)
  2. Describe what is meant by thought insertion (3)
  3. John tells his psychiatrist that he has been finding himself thinking of highly offensive comments about women that he would never say out loud. He tells the psychiatrist that he is convinced that his mobile phone is implanting these thoughts into his mind. Describe how the psychiatrist might describe John’s experience to him (3)