COVID-19 and earthquakes-related stress, quality of life, mental health, and internet-based addictive behaviour

Background: The prolonged stress experience caused by COVID-19 pandemic and two earthquakes led to increased Internet-based behavior, accompanied by a decrease in mental well-being and quality of life (QoL) in Croatian population. Our aim was to determine a) the direct association between QoL domains and overall and specific Internet use, problematic Internet use (PIU) and stress, anxiety, and depression, and b) the indirect association between increased overall and specific Internet use, PIU and different QoL domains through stress, anxiety, and depression symptoms in the adult population during prolonged stress.
Methods: A cross-sectional online survey conducted from September 30th to October 17th, 2021 included 1004 Croatian adults (82.2% women; mean age: 34.98±12.24 years) through non-probabilistic convenience sampling. The survey consisted of a self-reported questionnaire and PIU was assessed using Tao et al.’s criteria. The Impact of Event Scale, the Hospital Anxiety Depression Scale, and World Health Organization Quality of Life (WHOQoL) – BREF Scale were applied. Structural equation modelling was used to evaluate the model with Internet-based addictive behaviours as exogenous variables, various QoL domains as endogenous variables, and stress, anxiety, and depression symptoms as mediators.
Results:  The model demonstrated good fit and indicated that overall and specific Internet use increase, PIU, and anxiety and depression symptoms significantly explained all QoL domains (p<0.001 for all). Both increased overall and specific Internet use and PIU during the prolonged stress were directly associated with decreased QoL. These relationships were also indirectly mediated through increased anxiety and depression symptoms. 
Conclusion: Our findings revealed a direct association between Internet-based addictive behaviour and QoL and between increased overall and specific Internet use, PIU, and stress, anxiety, and depression and an indirect association between Internet-based addictive behaviour and QoL through stress, anxiety, and depression, leading to decreased QoL.
Future research should further clarify these relationships to better understand the contributing factors.