O1.6. AFFECTIVE DETERMINANTS OF LIFE-SPACE THROUGH GPS AND ECOLOGICAL MOMENTARY ASSESSMENT IN SCHIZOPHRENIA: WHAT GETS PEOPLE OUT OF THE HOUSE?
Authors: Parrish Emma , Depp Colin , Moore Raeanne C , Harvey Philip D , Holden Jason , Swendsen Joel , Granholm Eric 
Published: May 2020

Abstract

Background
Previous research employing global positioning satellite (GPS) data and ecological momentary assessment (EMA) has shown that greater aggregated time at home and less distance traveled (diminished life-space) were associated with poorer community functioning and with more severe negative symptoms in people with schizophrenia. Emotional experiences (e.g., pleasure or anxious avoidance) may reduce time spent outside of the home. We evaluated the associations between concurrent and time-lagged positive and negative affective experiences in relation to time at home and distance travelled in the community (life-space) among people with schizophrenia compared to healthy comparators (HCs).

Methods
Sixty HCs (mean age = 51.2, SD = 10.9) and 91 people with schizophrenia (mean age=52, SD=9), matched on demographic characteristics, completed in-lab assessments of symptoms, cognition, and functioning. They were then given a smartphone and completed EMA assessments 7 times daily for 7 days at stratified random intervals. EMA surveys included questions about daily life activities and affect. GPS coordinates were collected every 5 minutes, 24 hours a day, over the 7-day study period.

Results
Participants with schizophrenia spent more time at home than HCs (t = -4.95, p &lt; 0.001). Sadness and ratings of relaxation were not associated with distance traveled away or time spent at home. For HCs, happiness was associated with more distance traveled away as measured by GPS (B=6.85, SE= 3.04, Wald Chi-Square = 5.067, p=0.024). However, for people with schizophrenia, only greater nervousness ratings were associated with more distance from home (B=3.41, SE=1.30, Wald Chi-Square=6.88, p=0.009). Moreover, for people with schizophrenia, greater nervousness ratings were associated with more time spent at home (B=2.07, SE= 0.98, Wald Chi-Square=4.43, p=0.035), and greater nervousness also predicted that a person with schizophrenia would be at home at the next survey in lead analyses, (F(1, 3029)=7.533, p=0.006). Taken together, these results suggest both greater nervousness associated with greater distance away from home and anxious avoidance of leaving the home.

Discussion
For individuals with schizophrenia, greater overall anxiety was associated with reduced time spent out of the home, and when patients did leave the home, greater distance travelled was associated with greater nervousness. In contrast, HC participants experienced greater positive emotion with larger life-space. These data suggest a significant momentary temporal association of anxiety and behavior in schizophrenia, such that greater nervousness predicted an individual would be more likely to stay at home. These findings suggest avoidance of negative emotion may also contribute to diminished motivated behavior, which may even act as an emotion regulation strategy. Life-space, which can be measured readily over time by mobile devices, may be a novel target for rehabilitative interventions for anxious avoidance in schizophrenia.