Detecting improvements in acute psychotic symptoms using experience sampling methodology

This study aimed to explore the feasibility and validity of using experience sampling methodology (ESM, or ecological momentary assessment or mobile device signaling) to measure temporal changes and fluctuations in psychotic symptoms in patients with acute psychosis at the start of antipsychotic treatment.Twenty-six in-patients with delusions were assessed within 2 weeks of starting antipsychotic treatment using ESM on a personal digital assistant (PDA), seven times a day for 14 consecutive days. They were also interviewed at baseline, 1 week and 2 weeks after using standardized symptom measures.Sixteen patients (61.5%) completed at least one-third of the entries, with a compliance rate of 70.7%. Responses to the ESM items were internally consistent. At baseline, ESM and clinical ratings converged on suspiciousness and images, but not on voices and most of the delusion dimensions.Conducting ESM with patients in an acute episode was found to be feasible and internally valid. There is some divergence in symptom data obtained by ESM and standard symptom interviews, but ESM captures rich information about change that may not be represented by observer ratings.