Objective
Experience sampling assessments (multiple assessments per day for approximately one week) indicate that positive symptoms fluctuate over time in psychosis. Precursors, such as sleep problems or worrying, predict these fluctuations. To date, it remains unclear whether the same precursors predict symptom variability also during treatment in an online intervention for psychosis, using assessments lying temporally further apart.
Methods
Participants completed brief intermediate online self‐report assessments on their computers (up to every 7 days during a 2‐month waiting period and up to twice every 6 days during a 2‐month intervention period) within a randomized controlled trial. We monitored the course of paranoia, auditory verbal hallucinations, and their theory‐driven precursors worrying, negative affect, self‐esteem, self‐reported cognitive biases, and quality of sleep in n = 124 participants (M = 10.32 assessments per participant; SD = 6.07). We tested group differences regarding the course of the composite of precursors, group differences regarding the effect of the composite on subsequent momentary psychotic symptoms, and the effect of each individual precursor on subsequent psychotic symptoms, using (lagged) linear mixed models.
Results
The course composite precursors over time and their lagged effect on subsequent momentary psychotic symptoms did not differ between groups. During the intervention, increased worrying and decreased quality of sleep preceded heightened momentary psychotic symptoms.
Conclusion
The regression‐based design does not allow drawing causal conclusions. However, worrying and sleep problems likely represent underlying mechanisms of psychotic symptom variability during online psychosis treatment, indicating that experience sampling findings from everyday life generalize to interventions with assessments lying several days apart.
Practitioner points
Worrying and sleep problems represent important mechanisms of symptom fluctuations during an online intervention for people with psychosis.
Our findings further support the notion that worrying and sleep problems are important treatment targets in psychological interventions for people with psychosis.
Momentary levels of worrying and quality of sleep can signal subsequent fluctuations of psychotic symptom severity so practitioners should monitor these variables during treatment.
Worrying seems to predict subsequent paranoia specifically during treatment whereas quality of sleep predicts both paranoia and auditory verbal hallucinations