Capturing behavioral indicators of persecutory ideation using mobile technology

Most existing measures of persecutory ideation (PI) rely on infrequent in-person visits, and this limits their ability to assess rapid changes or real-world functioning. Mobile health (mHealth) technology may address these limitations. Little is known about passively sensed behavioral indicators associated with PI. In the current study, sixty-two participants with schizophrenia spectrum disorders completed momentary assessments of PI on a smartphone that also passively collected behavioral data for one year. Results suggested that PI was prevalent (n = 50, 82% of sample) but had infrequent incidence (25.2% of EMA responses). PI was also associated with changes in several passively sensed variables, including decreases in distance traveled (M_kilometers = -1.20, SD = 18.88), time spent in a vehicle (M_minutes = -4.15, SD = 49.59), length of outgoing phone calls (M_minutes = -0.79, SD = 13.13), time spent proximal to human speech (M_minutes = -6.26, SD = 153.03), and an increase in time sitting still (M_minutes = 4.04, SD = 94.69). The present study suggests changes associated with PI may be detectable by passive sensors, including reductions in moving or traveling, and time spent around others or in self-initiated phone conversations. These constructs might constitute risk for PI.