BACKGROUND: Disturbances in evidence gathering and disconfirmatory evidence integration have been associated with the presence of or propensity for delusions. Previous evidence suggests that these 2 types of reasoning bias might be differentially affected by antipsychotic medication. We aimed to investigate the effects of a dopaminergic agonist (L-dopa) and a dopaminergic antagonist (haloperidol) on evidence gathering and disconfirmatory evidence integration after single-dose administration in healthy individuals. METHODS: The study used a randomized, double-blind, placebo-controlled, 3-way crossover design. Participants were healthy individuals aged 18-40 years. We administered a new data-gathering task designed to increase sensitivity to change compared with traditional tasks. The Bias Against Disconfirmatory Evidence (BADE) task was used as a measure of disconfirmatory evidence integration. RESULTS: We included 30 individuals in our study. In the data-gathering task, dopaminergic modulation had no significant effect on the amount of evidence gathered before reaching a decision. In contrast, the ability of participants to integrate disconfirmatory evidence showed a significant linear dopaminergic modulation pattern (highest with haloperidol, intermediate with placebo, lowest with L-dopa), with the difference between haloperidol and L-dopa marginally reaching significance. LIMITATIONS: Although the doses used for haloperidol and L-dopa were similar to those used in previous studies, drug plasma level measurements would have added to the validity of findings. CONCLUSION: Evidence gathering and disconfirmatory evidence integration might be differentially influenced by dopaminergic agents. Our findings are in support of a dual-disturbance account of delusions and provide a plausible neurobiological basis for the use of interventions targeted at improving reasoning biases as an adjunctive treatment in patients with psychotic disorders.
RCT Entities:
BACKGROUND: Disturbances in evidence gathering and disconfirmatory evidence integration have been associated with the presence of or propensity for delusions. Previous evidence suggests that these 2 types of reasoning bias might be differentially affected by antipsychotic medication. We aimed to investigate the effects of a dopaminergic agonist (L-dopa) and a dopaminergic antagonist (haloperidol) on evidence gathering and disconfirmatory evidence integration after single-dose administration in healthy individuals. METHODS: The study used a randomized, double-blind, placebo-controlled, 3-way crossover design. Participants were healthy individuals aged 18-40 years. We administered a new data-gathering task designed to increase sensitivity to change compared with traditional tasks. The Bias Against Disconfirmatory Evidence (BADE) task was used as a measure of disconfirmatory evidence integration. RESULTS: We included 30 individuals in our study. In the data-gathering task, dopaminergic modulation had no significant effect on the amount of evidence gathered before reaching a decision. In contrast, the ability of participants to integrate disconfirmatory evidence showed a significant linear dopaminergic modulation pattern (highest with haloperidol, intermediate with placebo, lowest with L-dopa), with the difference between haloperidol and L-dopa marginally reaching significance. LIMITATIONS: Although the doses used for haloperidol and L-dopa were similar to those used in previous studies, drug plasma level measurements would have added to the validity of findings. CONCLUSION: Evidence gathering and disconfirmatory evidence integration might be differentially influenced by dopaminergic agents. Our findings are in support of a dual-disturbance account of delusions and provide a plausible neurobiological basis for the use of interventions targeted at improving reasoning biases as an adjunctive treatment in patients with psychotic disorders.
Authors: Mahesh Menon; Lena Catherine Quilty; John Anthony Zawadzki; Todd Stephen Woodward; Helen Moriah Sokolowski; Heather Shirley Boon; Albert Hung Choy Wong Journal: Cogn Neuropsychiatry Date: 2012-07-04 Impact factor: 1.871
Authors: Philippa A Garety; Daniel Freeman; Suzanne Jolley; Graham Dunn; Paul E Bebbington; David G Fowler; Elizabeth Kuipers; Robert Dudley Journal: J Abnorm Psychol Date: 2005-08
Authors: M R Broome; L C Johns; I Valli; J B Woolley; P Tabraham; C Brett; L Valmaggia; E Peters; P A Garety; P K McGuire Journal: Br J Psychiatry Suppl Date: 2007-12
Authors: Bruno B Averbeck; Simon Evans; Viraj Chouhan; Eleanor Bristow; Sukhwinder S Shergill Journal: Schizophr Res Date: 2011-04 Impact factor: 4.939
Authors: Suzanne H So; Daniel Freeman; Graham Dunn; Shitij Kapur; Elizabeth Kuipers; Paul Bebbington; David Fowler; Philippa A Garety Journal: J Abnorm Psychol Date: 2011-09-12
Authors: Nico Pytlik; Daniel Soll; Klaus Hesse; Steffen Moritz; Andreas Bechdolf; Jutta Herrlich; Tilo Kircher; Stefan Klingberg; Martin W Landsberg; Bernhard W Müller; Georg Wiedemann; Andreas Wittorf; Wolfgang Wölwer; Michael Wagner; Stephanie Mehl Journal: BMC Psychiatry Date: 2020-11-23 Impact factor: 3.630