## 6 Conclusions  
Social media has now been integrated into our daily lives and has affected our mental health. Therefore, we designed this study to clarify whether young adults' social media use and SWB changed during the COVID-19 pandemic and whether the relationships differed depending on the combination of social media platforms used. Our results showed that even during the COVID-19 pandemic, regardless of social media use patterns, receiving more social support from others and decreasing people's depression tendencies helped improve their SWB. Moreover, for digital native generations (our study's participants ranged from 18 to 25 years old), showing different sides of the \"self\" online would help improve SWB when using different social media. These results provide a foundation for public health authorities to develop new support programs to help digital natives gain social support and find ways to maintain their mental health by balancing their online and offline communication, as well as shed light on new methods of handling social media addiction based on their social media use patterns. However, middle-aged and older adults may differ, as the latter have lower levels of self-pluralism [43]. Therefore, it would be ideal to conduct further research on other age groups to make comparisons and increase the robustness of this study's implications. In particular, we collected our data in Japan, which has its own specific social media platform preferences (such as Facebook being less popular and LINE being the most popular), and the results may have been influenced by the local users' preferences and cultural background. However, it is necessary to note that except for LINE, the other social media platforms investigated in this study, such as Twitter, Instagram, Discord,and TikTok, are popular around the world, which makes our results more generalizable. Additionally, our analysis was based on the usage style of the platform, i.e., we focused on how people use different platforms simultaneously, such as the purposes of usage and types of posts, etc., which allows our findings based on usage to be extended to other social media platforms, making them generalizable to other countries and regions. For business sectors, our findings also show that social media use patterns are related to users' personalities. Therefore, businesses can consider developing social marketing campaigns by targeting their potential users' personalities using that particular social media use pattern. Social media app developers can also use such information to develop and refine their apps to provide services that fit their potential users. This study has several limitations, with the primary one being the small sample size related to social media use patterns. As we collected the data using the three-wave panel survey format, we faced a significant decline in sample size over time, which is especially common in longitudinal studies. Although we had 800 to 1,600 participants in the 3-year survey period, most of the social media use patterns did not have a sufficient number of participants. Even when selecting the three most frequently used social media use patterns for our analysis, we still did not have enough participants in some cases to study gender effects. This is a topic for future research. Furthermore, as a research study, we only examined a selected set of factors. Other factors, such as users' FTF social networks and interpersonal relationships, might affect their social media use. Therefore, we have included these as potential factors to study in future projects. Additionally, as previous studies have pointed out, the relationship between social media use and mental health is complex, as many mediating factors need to be considered, including social connections and the social environment. Therefore, future studies should include such factors when examining the relationship between social media use and mental health, including their combination with other approaches. Conceptualization, S.Y. ; methodology, S.Y. ; validation, S.Y.