High psychosis liability is associated with altered autonomic balance during exposure to Virtual Reality social stressors

Background: Social stressors are associated with an increased risk of psychosis. Stress sensitisation is thought to be an underlying mechanismand may be reflected in an altered autonomic stress response. Using an experimental Virtual Reality design, the autonomic stress response to social stressorswas examined in participantswith different liability to psychosis.

Method: Fifty-five patients with recent onset psychotic disorder, 20 patients at ultra-high risk for psychosis, 42 siblings of patientswith psychosis and 53 controls were exposed to social stressors (crowdedness, ethnicminority status and hostility) in a Virtual Reality environment. Heart rate variability parameters and skin conductance levels were measured at baseline and during Virtual Reality experiments.

Results: High psychosis liability groups had significantly increased heart rate and decreased heart rate variability compared to low liability groups both at baseline and during Virtual Reality experiments. Both low frequency (LF) and high frequency (HF) power were reduced, while the LF/HF ratiowas similar between groups. The number of virtual social stressors significantly affected heart rate, HF, LF/HF and skin conductance level. There was no interaction between psychosis liability and amount of virtual social stress.

Conclusion: High liability to psychosis is associated with decreased parasympathetic activity in virtual social environments, which reflects generally high levels of arousal, rather than increased autonomic reactivity to social stressors. (C) 2016 Elsevier B.V. All rights reserved.