Our findings showed that a higher perceived negative impact of COVID-19 may be predicted as decreasing well-being and increasing ill-being. The association between the FTP or the PHTP and self-control further mediated the role of the perceived impact on mental health when well-being and ill-being were considered simultaneously. Specifically, the mediating effect of the FTP on ill-being was fully mediated by self-control.
Students who experienced significantly high impacts of COVID-19 reported higher levels of ill-being and lower levels of well-being. These results are consistent with those of previous studies during the outbreak stage of the COVID-19 pandemic [11, 43]. Our survey was conducted late into the outbreak of the COVID-19 pandemic in China. The low infection rate (daily infections below 20) does not mean that the changes COVID-19 has had on people’s lives can be ignored. College students continue to experience the strain of the pandemic. Our results showed a tendency whereby individuals who self-reported being more impacted by COVID-19 were more likely to hold PHTPs and found it harder to maintain FTPs, thereby changing their levels of well-being. Although a causal explanation is difficult to derive from cross-sectional studies, the results are consistent with the findings of previous studies in that the COVID-19 pandemic has modified the way in which people perceive their future .
Considering the mediating effect of TPs on well-being, the PHTP demonstrated adaptability to well-being under the influence of the FTP and self-control model, consistent with the findings of previous studies . Although these results are inconsistent with the findings of previous studies [20, 44], the FTP had a significant positive impact on well-being. A possible explanation is that during the on-going COVID-19 pandemic, focusing on the future may make people feel more hopeful and optimistic than ever before , which may significantly increase their levels of well-being.
Regarding the mediating effect of TPs on ill-being, only the PHTP had a significant effect. Unlike the findings of previous studies whereby individuals with FTPs experienced less negative affects , having an FTP may not reduce negative emotion and anxiety directly. One possible reason for this involves the context of COVID-19 in that when individuals are generally under stress, they experience more negative emotions than before. Another possible explanation is that well-being and ill-being are two different constructs contrary to two ends on a continuum . Furthermore, we established that the FTP can positively predict well-being directly, but it negatively predicts ill-being through self-control.
Additionally, the results of this study demonstrated that self-control had a direct mediating effect on the perceived impact of COVID-19 on well-being and ill-being. Environmental changes may directly reduce self-control among individuals, thereby increasing the risks of ill-being and reducing the benefits of well-being. In our TP and self-control model, self-control was a crucial protective factor for well-being during the COVID-19 pandemic, and it functioned through a mediating mechanism, as demonstrated through our mediation model (well-being and ill-being), whose results differ from the findings of a previous study showing a moderating effect . This result supported the motivational explanation of self-control . We concluded that self-control is an option based on value and various internal cues, such as emotions, demands, and beliefs and various external cues, such as motivations, social pressure, and the environment.
Finally, the chain-mediated effects of TPs and self-control were significant, as they pertained to the perceived impacts of COVID-19 on well-being/ill-being. In the face of the negative impacts of the COVID-19 pandemic, the findings of this study indicated that the utility of emphasising only the FTP is limited. Therefore, the relationship between the FTP and self-control must be considered.
This study provides further insight and theoretical contributions. First, the results provided empirical evidence regarding the dual-factor system of mental health theory in which well-being and ill-being are two different structures, as opposed to two ends of one dimension. Owing to the COVID-19 pandemic, the way in which individuals perceive time and their futures  has been altered significantly, especially among college students who must take online classes at home. Having been removed from the campus environment, such students experience a conflict between ‘striving for the future’ or ‘staying in the present’ daily, which may affect their mental health. Second, contrary to the results of previous studies , the FTP provided additional positive emotions and increased levels of life satisfaction by following a direct path. There was no direct connection between the FTP and ill-being, thereby indicating that following an indirect path was significantly associated with ill-being. Additionally, the PHTP did not demonstrate a stable protection for mental health. Focusing on a PHTP had a positive effect on well-being, but it also increased ill-being, which requires additional consideration with regards to the context of the COVID-19 pandemic. Third, the relationship between the FTP or the PHTP and self-control has been proven and enriched. Therefore, through a multiple mediation model, this study provides a deeper understanding of the motivational interpretation rather than the ability-related interpretation of self-control, as it pertains to TPs. Specifically, the multiple mediating effects of the FTP and self-control have a significant impact on ill-being, thereby indicating that the association between the FTP and self-control has a high protective effect in the context of the current COVID-19 pandemic.
In addition to providing practical interpretations of the theories involved, this study provides further insight into clinical practice and public health management strategies associated with TPs. This study provides suggestions for ensuring the enhanced exertion of self-control in practical contexts. We believe that increased levels of self-control among students may be achieved by enhancing their FTPs to protect their mental health. Furthermore, excessive emphasis on the negative effects of COVID-19 may reduce self-control among college students, thereby harming their mental health. Therefore, in terms of policy publicity, emphasising future changes brought about by active pandemic prevention and showing confidence in the future may help individuals to increasingly comply with pandemic prevention policies and enhance their confidence.
Limitations and directions for future research
This study has several limitations. First, the cross-sectional design does not allow for conclusions regarding causation. Therefore, additional lab-based experiments are required in the future to manipulate participants’ TPs in laboratory environments. Second, this study relied on convenience sampling, which may limit the generalisation of our findings beyond those involving college students. Third, based on the relationship between self-control and the influence of the COVID-19 pandemic on TPs, only the FTP and the PHTP were considered in the model. Other types of TPs could be included in future studies. Future studies could focus on exploring additional moderating variables, such as social support and personality factors, to better understand the influence of COVID-19 on mental health.