Autonomic reactivity to psychosocial stress in individuals with problematic Internet use

Abstract

Background: The link between stress reactivity and subjective urge/craving has been less systematically examined in behavioral addictions than in substance use disorders. The present study investigated whether problematic Internet users (PIU) show enhanced autonomic stress reactivity than non-PIU, indexed by lower Heart Rate Variability (HRV) and higher Skin Conductance Level (SCL) reactivity during the Trier Social Stress Test (TSST), and whether greater reactivity is related to stronger urge/craving. Methods: Based on their Internet Addiction Test scores, participants were divided into PIU (N=24) and non-PIU (N=21). Their heart rate and skin conductance were continuously recorded during baseline, the TSST, and recovery. HRV and SCL reactivity during the TSST were measured as autonomic indices of the stress response. “Urge to be online†ratings were collected using a Likert scale before and after the TSST. A mixed-model approach was used to estimate group differences in stress reactivity. Findings: HRV was significantly lower in PIU than non-PIU during baseline, but not during the TSST and recovery. Furthermore, only among PIU a significant negative correlation emerged between HRV during recovery and urge ratings after the test. No group differences emerged for SCL. Discussion: Our findings suggest that problems in controlling one’s use of the Internet is related to impaired self-regulation through parasympathetic mechanisms. Reduced autonomic flexibility may mediate the known negative impact of problematic internet use on physical health. HRV-biofeedback protocols may be developed as an adjunct intervention to prevent and/or reduce such negative effects.