The recent paper by Upthegrove et al ^{Reference Upthegrove, Chard, Jones, Gordon-Smith, Forty and Jones1} provided an extensive study evaluating the association of childhood events with later development of psychosis. Hypotheses were partially supported and demonstrated that although childhood trauma (e.g. family disruption, abuse) was not associated with the development of psychosis, the authors did find a significant association between childhood abuse and hallucinations that were mood congruent or abusive in their content. More specifically, the authors identified that childhood sexual abuse, experiencing a victimising event (such as bullying) and death of a loved one were all significantly linked to hallucinations, even after controlling for the effects of cannabis use. The authors also suggest that childhood events did not show any association with the development of depressive or persecutory delusions.

This observed result is suggested to question cognitive models of delusions, where the precipitator, i.e. childhood trauma, leads to a state of arousal in the individual, which leads to inner–outer confusion and can cause unusual sensory/perceptual experiences. ^{Reference Freeman, Garety, Kuipers, Fowler and Bebbington2} Cognitive models suggest that it is the cognitive biases around these unusual experiences, the search for meaning of these experiences, and the core beliefs about the self, others and the world, which lead to the explanation that gives rise to the ‘threat belief’ or persecutory delusion. Therefore the authors suggest that it may be later-life experiences rather than childhood experiences which feed into this model, leading to the delusion.

Instead, it is possible that the neuropsychological theory of mind ^{Reference Frith3} can provide an alternative explanation for the development of persecutory delusions, whereby the individual develops false beliefs about the intentions of other people due to impairments in mentalising, which leads to the development of the ‘threat belief’ or delusion. ^{Reference Blackwood, Howard, Bentall and Murray4} Frith ^{Reference Frith3} proposed that patients with schizophrenia develop theory-of-mind skills appropriately, but suggested that they experience a loss of these skills during a psychotic episode. Further research into this area has demonstrated that theory-of-mind deficits are not simply ‘state characteristics’, as patients with schizophrenia in remission still display significantly impaired theory-of-mind skills compared with healthy controls, demonstrating that theory-of-mind impairments are likely to be trait characteristics. ^{Reference Bora, Yucel and Pantelis5} It is possible that it is a combination of adverse childhood experiences and impaired theory-of-mind skills that have a cumulative effect of leading to persecutory delusions, hence the findings in Upthegrove et al's study.