Changes in delusions in the early phase of antipsychotic treatment - an experience sampling study.

It has been suggested that different aspects of delusions (conviction, distress, preoccupation) respond to treatment at different rates, and that the cognitive bias of 'Jumping to Conclusions' (JTC) may predict treatment outcome. This study investigates changes in delusion dimensions using Experience Sampling Methodology (ESM) and the role of JTC as a predictor of change during the initial 2 weeks of antipsychotic treatment on admission to hospital. Sixteen acute patients with delusions were assessed seven times per day for 14 days using computerised ESM. ESM assessed moment-by-moment experiences of affect, psychotic symptoms, and delusion dimensions. Clinical ratings were completed at baseline, 1 week and 2 weeks later. The 'beads' task was used to measure JTC at baseline. Delusion dimensions improved over the two weeks of antipsychotic treatment and admission to hospital. Different delusional dimensions changed at different rates, with distress and disruption being more responsive than conviction and preoccupation on both PSYRATS and ESM ratings. Eight out of 16 participants showed a JTC bias on the beads task at baseline. Exploratory analyses showed that JTC predicted changes in the ESM ratings of delusion conviction and distress, suggesting that reasoning biases may predict treatment response.