Persecutory delusions may be unfounded threat beliefs maintained by safety-seeking behaviours that prevent disconfirmatory evidence being successfully processed. Use of virtual reality could facilitate new learning.

To test the hypothesis that enabling patients to test the threat predictions of persecutory delusions in virtual reality social environments with the dropping of safety-seeking behaviours (virtual reality cognitive therapy) would lead to greater delusion reduction than exposure alone (virtual reality exposure).

Conviction in delusions and distress in a real-world situation were assessed in 30 patients with persecutory delusions. Patients were then randomised to virtual reality cognitive therapy or virtual reality exposure, both with 30 min in graded virtual reality social environments. Delusion conviction and real-world distress were then reassessed.

In comparison with exposure, virtual reality cognitive therapy led to large reductions in delusional conviction (reduction 22.0%, P = 0.024, Cohen's d = 1.3) and real-world distress (reduction 19.6%, P = 0.020, Cohen's d = 0.8).

Cognitive therapy using virtual reality could prove highly effective in treating delusions.

To examine whether parents offering a sticker reward to their child to taste a vegetable the child does not currently consume is associated with improvements in children's liking and consumption of the vegetable.

A randomized controlled trial evaluated the effectiveness of exposure only (EO) and exposure plus reward (E + R), relative to a control group, on children's liking and consumption of a target vegetable. Assessments were conducted at baseline and 2 weeks from baseline (post-intervention). Follow-up assessments were conducted at 4 weeks and 3 months from baseline.

The study took place in Adelaide, South Australia. Participants were self-selected in response to local media advertisements seeking to recruit parents finding it difficult to get their children to eat vegetables.

Participants were 185 children (110 boys, seventy-five girls) aged 4–6 years and their primary caregiver/parent (172 mothers, thirteen fathers).

The E + R group was able to achieve more days of taste exposure. Both EO and E + R increased liking at post-intervention compared with control and no further change occurred over the follow-up period. All groups increased their intake of the target vegetable at post-intervention. Target vegetable consumption continued to increase significantly over the follow-up period for E + R and control but not for EO.

The findings provide support for the effectiveness of using a sticker reward with a repeated exposure strategy. In particular, such rewards can facilitate the actual tastings necessary to change liking.

Judging whether we can trust other people is central to social interaction, despite being error-prone. A fear of others can be instilled by the contemporary political and social climate. Unfounded mistrust is called paranoia, and in severe forms is a central symptom of schizophrenia.

To demonstrate that individuals without severe mental illness in the general population experience unfounded paranoid thoughts, and to determine factors predictive of paranoia using the first laboratory method of capturing the experience.

Two hundred members of the general public were comprehensively assessed, and then entered a virtual reality train ride populated by neutral characters. Ordinal logistic regressions (controlling for age, gender, ethnicity, education, intellectual functioning, socio-economic status, train use, playing of computer games) were used to determine predictors of paranoia.

The majority agreed that the characters were neutral, or even thought they were friendly. However, a substantial minority reported paranoid concerns. Paranoia was strongly predicted by anxiety, worry, perceptual anomalies and cognitive inflexibility.

This is the most unambiguous demonstration of paranoid ideation in the general public so far. Paranoia can be understood in terms of cognitive factors. The use of virtual reality should lead to rapid advances in the understanding of paranoia.

Virtual reality provides a means of studying paranoid thinking in controlled laboratory conditions. However, this method has not been used with a clinical group

To establish the feasibility and safety of using virtual reality methodology in people with an at-risk mental state and to investigate the applicability of a cognitive model of paranoia to this group

Twenty-one participants with an at-risk mental state were assessed before and after entering a virtual reality environment depicting the inside of an underground train

Virtual reality did not raise levels of distress at the time of testing or cause adverse experiences over the subsequent week. Individuals attributed mental states to virtual reality characters including hostile intent. Persecutory ideation in virtual reality was predicted by higher levels of trait paranoia, anxiety, stress, immersion in virtual reality, perseveration and interpersonal sensitivity

Virtual reality is an acceptable experimental technique for use with individuals with at-risk mental states. Paranoia in virtual reality was understandable in terms of the cognitive model of persecutory delusions