Holiday Internet Usage Time and the Risk of Internet Addiction Tendency among Working Adults in their 30s in Japan

Round 1

Reviewer 1 Report

The present manuscript has investigated a very interesting and less studied topic, the risk of internet addiction in working adults. Future developments could help deepen our knowledge of functional adults and their relationship with the Internet. I particularly appreciated differentiating between weekdays and holiday internet use.

The punctuation in the Results section might be improved, especialy lines 146-151.

Author Response

【Reviewer 1】

The present manuscript has investigated a very interesting and less studied topic, the risk of internet addiction in working adults. Future developments could help deepen our knowledge of functional adults and their relationship with the Internet. I particularly appreciated differentiating between weekdays and holiday internet use.

Comments on the Quality of English Language

The punctuation in the Results section might be improved, especialy lines 146-151.

[Response]

Thank you for your important suggestion.

The title was changed as below to clarify the target of our study, which focused on holiday Internet usage time. “Holiday Internet usage time and the risk of Internet addiction tendency among 30s working adults in Japan”

According to your suggestion, we have improved the punctuation in the Results section in lines 159-165.

“This result is valid regardless of gender or type of SNS when the IAT is used (Females: r = 0.295, p = 0.017, Males: r = 0.341, p = 0.014; and SNS -: r = 0.338, p = 0.003, SNS +: r = 0.310, p = 0.048)The SAS is also weakly positively correlated among women or those who do not primarily use SNS (Females: r = 0.408, p = <0.001, Males: r = 0.257, p = 0.054; and SNS -: r = 0.398, p = <0.001, SNS +: r = 0.262, p = 0.085). Personality traits are weakly positively correlated with weekend SNS + Internet use (r = 0.43, p = 0.005).”

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear authors,

I am honored to review your article, titled "Personality trait and sex differences in Internet usage among young working adults in Japan".

The paper presents an interesting topic.

In this regard, I must mention that the references do not follow the journal's standards and are highly obsolete. In this sense, they should include among many references from the last two years, both in the introduction and in the discussion.

The introduction is little worked and is very superficial. The theme has been highly investigated, so it is necessary to deepen the current state of the question of each of the constructs.

Regarding the methodology, they reflect the sample and its characteristics but do not clearly and manifestly state the inclusion criteria, the type of sampling, or the assumed sampling error, which, if applicable, is essential given the very small size of the sample. .

Likewise, the validity and reliability of the instruments used, or the tests used for the correlation of variables are not clearly and precisely exposed, they only expose the univariate contrast tests.

Regarding the discussions, each of the results is not discussed in depth, but a superficial synthesis is carried out. It must be deepened and include enough studies for and/or against.

Finally, the conclusions are not consistent in relation to the rest of the paper, it must be concluded by highlighting the most relevant of each variable analyzed and contrasted.

Author Response

【Reviewer 2】

Dear authors,

I am honored to review your article, titled "Personality trait and sex differences in Internet usage among young working adults in Japan".

The paper presents an interesting topic.

In this regard, I must mention that the references do not follow the journal's standards and are highly obsolete. In this sense, they should include among many references from the last two years, both in the introduction and in the discussion.

The introduction is little worked and is very superficial. The theme has been highly investigated, so it is necessary to deepen the current state of the question of each of the constructs.

Regarding the methodology, they reflect the sample and its characteristics but do not clearly and manifestly state the inclusion criteria, the type of sampling, or the assumed sampling error, which, if applicable, is essential given the very small size of the sample. .

Likewise, the validity and reliability of the instruments used, or the tests used for the correlation of variables are not clearly and precisely exposed, they only expose the univariate contrast tests.

Regarding the discussions, each of the results is not discussed in depth, but a superficial synthesis is carried out. It must be deepened and include enough studies for and/or against.

Finally, the conclusions are not consistent in relation to the rest of the paper, it must be concluded by highlighting the most relevant of each variable analyzed and contrasted.

[Response]

Thank you for pointing out the issue of the manuscript and helpful comments.

The title was changed as below to clarify the target of our study, which focused on holiday Internet usage time. “Holiday Internet usage time and the risk of Internet addiction tendency among 30s working adults in Japan”

The following recent papers have been cited and added to the introduction and discussion.

29. Lozano-Blasco, R., Robres, A. Q., & Sánchez, A. S. Internet addiction in young adults: A meta-analysis and systematic review. Computers in Human Behavior (2022) 130, 107201. https://doi.org/10.1016/j.chb.2022.107201

30. Ratan, Z. A., Parrish, A.-M., Zaman, S. Bin, Alotaibi, M. S., & Hosseinzadeh, H. Smartphone Addiction and Associated Health Outcomes in Adult Populations: A Systematic Review. International Journal of Environmental Research and Public Health (2021) 18(22). https://doi.org/10.3390/ijerph182212257

31. Nakayama, H., Ueno, F., Mihara, S., Kitayuguchi, T., & Higuchi, S. Relationship between problematic Internet use and age at initial weekly Internet use. Journal of Behavioral Addictions (2020), 9(1), 129–139. https://doi.org/10.1556/2006.2020.00009

32. Tsumura, H., Kanda, H., Sugaya, N., Tsuboi, S., & Takahashi, K. Prevalence and Risk Factors of Internet Addiction Among Employed Adults in Japan. J Epidemiol (2018), 28(4), 202–206. https://doi.org/10.2188/jea.JE20160185

33. Zink, J., Belcher, B. R., Imm, K., & Leventhal, A. M. The relationship between screen-based sedentary behaviors and symptoms of depression and anxiety in youth: a systematic review of moderating variables. BMC Public Health (2020), 20(1), 472. https://doi.org/10.1186/s12889-020-08572-1

34. Ryder, A. G., Costa, P. T., & Bagby, R. M. Evaluation of the SCID-II Personality Disorder Traits for DSM-IV: Coherence, Discrimination, Relations With General Personality Traits, and Functional Impairment. Journal of Personality Disorders (2007), 21(6), 626–637. https://doi.org/10.1521/pedi.2007.21.6.626

35. Burkauskas, J., Gecaite-stonciene, J., Demetrovics, Z., Griffiths, M. D., & Király, O. Prevalence of problematic Internet use during the coronavirus disease 2019 pandemic. Current Opinion in Behavioral Sciences (2022), 46, 101179. https://doi.org/10.1016/j.cobeha.2022.101179

36. Paulus, F. W., Joas, J., Gerstner, I., Kühn, A., Wenning, M., Gehrke, T., Burckhart, H., Richter, U., Nonnenmacher, A., Zemlin, M., Lücke, T., Brinkmann, F., Rothoeft, T., Lehr, T., & Möhler, E. Problematic Internet Use among Adolescents 18 Months after the Onset of the COVID-19 Pandemic. Children (2022), 9(11), 1724. https://doi.org/10.3390/children9111724

37. Oka, T., Hamamura, T., Miyake, Y., Kobayashi, N., Honjo, M., Kawato, M., Kubo, T., & Chiba, T. Prevalence and risk factors of internet gaming disorder and problematic internet use before and during the COVID-19 pandemic: A large online survey of Japanese adults. Journal of Psychiatric Research (2021), 142, 218–225. https://doi.org/10.1016/j.jpsychires.2021.07.054

We have clearly indicated the inclusion and exclusion criteria in the text. ‘The inclusion criterion is " relatively healthy working adults " and the exclusion criterion is "those who are not working."’ We have not established further detail criteria.

We used a convenience sampling method. We noted the following in lines 76-77: “A total of 156 workers participated in this study according to a convenience sampling method.”

We have shown the sampling error as follows in lines 83-85: “Twenty-seven participants who did not respond to the questionnaire on Internet usage were excluded.”

We added the tests for the correlation following sentence in lines 140-141 and lines 146:

“Correlation estimates (r) were calculated by Pearson’s product moment correlation or Spearman's rank-order correlation or Pearson’s correlation analysis.”

“We set the level of significance at p < 0.05 (two-tailed).”

Author Response File: Author Response.pdf

Reviewer 3 Report

REVIEW_Personality trait and sex differences in Internet usage among young working adults in Japan 

I would recommend changing the name "sex" to "gender". 

Abstract. Introduction part: It is not clear why the authors talk about "adolescents, especially students..." when the study sample is 30-39-year-old people and the title mentions that they are "young working adults". And at The purpose does not correspond to the topic of the study. The goal cannot be "... to elucidate the less association between Internet usage time and mental health problems...", therefore firstly, the title should be clarified and put "Internet usage time", not in general - Internet usage, which includes a lot of aspects, secondly, personality trait is not the same as "mental health problems". This is absolutely not clear. It is also not clear why depression appears, which is not mentioned in the title. Methods: mentions only "A correlation analysis focused on sex and difference between weekdays and holidays was conducted", which is not related to the topic of the study, but does not mention such a variable as Personality trait. And the conclusion "Our pilot findings provide clues to the pathophysiology of Internet and smartphone addiction, especially among adults" is uncritical, because the study does not study anything from pathophysiology. 

1. Introduction 

Adolescent studies are not relevant to this study and the authors should not refer to them (5,6,8,9), but use studies in which adults participated. The authors only point out that there is little research in adults, citing two studies. This should be supplemented with relevant literature. If a meta-analysis has been performed, there cannot be too few studies. The goal should be corrected so that it is clear what is going to be studied. And the introduction part should be supplemented accordingly - it is not clear what "mental health" problems are going to be studied. 

2. Materials and Methods 

2.1. Participants 

In this section, the respondents should be described in more detail - Mean age, SD, gender, etc. But the procedure should be described in another section. Why did the authors choose this particular age group? 

2.2. Measures 

It is not clear what the "Internet Usage Time" survey is, whether it was created by the authors, what questions it includes, whether it is adapted or validated, etc. It is also not clear why four depression surveys should be used, it is not explained anywhere. Also, the introduction part does not explain why depression should be studied, except for one short remark. Above, the authors talk about personality trait, but use personality disorder questionnaire. Trait is not a disorder! How did the authors determine the trait? No Cronbach alphas were specified for any survey. 

3. Results 

The authors tend to indicate that "Women in the sample had higher depressive tendency than the men in the sample", but in some of the surveys used, these indicators are not statistically significant, and in one, they are lower for women. The first thing to do would be to see if these polls correlate with each other. I would recommend getting acquainted with the publication: https://www.researchgate.net/publication/5775311_Evaluation_of_the_SCID-II_Personality_Disorder_Traits_for_DSM-IV_Coherence_Discrimination_Relations_With_General_Personality_Traits_and_Functional_Impairment 

What is SIGH-17 in the Table 2? The results are unclear, what do they really show? 

4. Discussion 

The authors make claims although the results are not generalizable to the population because the sample is too small to make any claims. The discussion again refers to adolescent studies. Thirty year olds are not teenagers! The discussion part should be organized according to the age of the research sample. 

5. Conclusions 

The authors cannot state “…reported among Japanese youths” with such a small sample. The results of the study can only be applied to the study sample, not to all young people. The conclusion "...This result may lead to an enhanced understanding of the pathophysiology..." is also inadequate for the specific study. 

Author Response

【Reviewer 3】

Personality trait and sex differences in Internet usage among young working adults in Japan

I would recommend changing the name "sex" to "gender".

Abstract. Introduction part: It is not clear why the authors talk about "adolescents, especially students..." when the study sample is 30-39-year-old people and the title mentions that they are "young working adults". And at The purpose does not correspond to the topic of the study. The goal cannot be "... to elucidate the less association between Internet usage time and mental health problems...", therefore firstly, the title should be clarified and put "Internet usage time", not in general - Internet usage, which includes a lot of aspects, secondly, personality trait is not the same as "mental health problems". This is absolutely not clear. It is also not clear why depression appears, which is not mentioned in the title. Methods: mentions only "A correlation analysis focused on sex and difference between weekdays and holidays was conducted", which is not related to the topic of the study, but does not mention such a variable as Personality trait. And the conclusion "Our pilot findings provide clues to the pathophysiology of Internet and smartphone addiction, especially among adults" is uncritical, because the study does not study anything from pathophysiology.

1. Introduction

Adolescent studies are not relevant to this study and the authors should not refer to them (5,6,8,9), but use studies in which adults participated. The authors only point out that there is little research in adults, citing two studies. This should be supplemented with relevant literature. If a meta-analysis has been performed, there cannot be too few studies. The goal should be corrected so that it is clear what is going to be studied. And the introduction part should be supplemented accordingly - it is not clear what "mental health" problems are going to be studied.

2. Materials and Methods

2.1. Participants

In this section, the respondents should be described in more detail - Mean age, SD, gender, etc. But the procedure should be described in another section. Why did the authors choose this particular age group?

2.2. Measures

It is not clear what the "Internet Usage Time" survey is, whether it was created by the authors, what questions it includes, whether it is adapted or validated, etc. It is also not clear why four depression surveys should be used, it is not explained anywhere. Also, the introduction part does not explain why depression should be studied, except for one short remark. Above, the authors talk about personality trait, but use personality disorder questionnaire. Trait is not a disorder! How did the authors determine the trait? No Cronbach alphas were specified for any survey.

3. Results

The authors tend to indicate that "Women in the sample had higher depressive tendency than the men in the sample", but in some of the surveys used, these indicators are not statistically significant, and in one, they are lower for women. The first thing to do would be to see if these polls correlate with each other. I would recommend getting acquainted with the publication: https://www.researchgate.net/publication/5775311_Evaluation_of_the_SCID-II_Personality_Disorder_Traits_for_DSM-IV_Coherence_Discrimination_Relations_With_General_Personality_Traits_and_Functional_Impairment

What is SIGH-17 in the Table 2? The results are unclear, what do they really show?

4. Discussion

The authors make claims although the results are not generalizable to the population because the sample is too small to make any claims. The discussion again refers to adolescent studies. Thirty year olds are not teenagers! The discussion part should be organized according to the age of the research sample.

5. Conclusions

The authors cannot state “…reported among Japanese youths” with such a small sample. The results of the study can only be applied to the study sample, not to all young people. The conclusion "...This result may lead to an enhanced understanding of the pathophysiology..." is also inadequate for the specific study.

[Response]

We really appreciate you for your productive suggestions and comments regarding our manuscript. According to your suggestion, we have changed the name "sex" to "gender".

The title was changed as below to clarify the target of our study, which focused on holiday Internet usage time. “Holiday Internet usage time and the risk of Internet addiction tendency among 30s working adults in Japan”

Abstract.

We change “Internet usage” into “Internet usage time” according to your suggestion in title, abstract and discussion.

We also change “mental health problems” into “psychometric tests” in abstract, introduction, and method.

This survey may be difficult to discuss pathophysiology because the present study did not focus on the diseases of Internet and smartphone addiction as you pointed out. We change “pathophysiology” into “mental health” in abstract and conclusion.

1. Introduction

Following your suggestion, we have added to the text and cited surveys of the relationship between Internet and smartphone dependence among adults.

In lines 42-45.

“Differences in working status have been noted in the association between Internet usage time and compulsive Internet use among adults (31). A recent survey of working adults in Japan has indicated that groups at risk for Internet ad-diction tended to spend more time using the Internet (32).”

In lines 60-63.

“Previous analyses of Internet addiction among adults have primarily focused on adults in their 20s. Also, most analyses of smartphone addiction have focused on adults in their 20s (29,30); however, studies focusing on working adults over 30s are very limited.”

31. Nakayama, H., Ueno, F., Mihara, S., Kitayuguchi, T., & Higuchi, S. Relationship between problematic Internet use and age at initial weekly Internet use. Journal of Behavioral Addictions (2020), 9(1), 129–139. https://doi.org/10.1556/2006.2020.00009
32. Tsumura, H., Kanda, H., Sugaya, N., Tsuboi, S., & Takahashi, K. Prevalence and Risk Factors of Internet Addiction Among Employed Adults in Japan. J Epidemiol (2018), 28(4), 202–206. https://doi.org/10.2188/jea.JE20160185
33. Lozano-Blasco, R., Robres, A. Q., & Sánchez, A. S. Internet addiction in young adults: A meta-analysis and systematic review. Computers in Human Behavior (2022) 130, 107201. https://doi.org/10.1016/j.chb.2022.107201
34. Ratan, Z. A., Parrish, A.-M., Zaman, S. Bin, Alotaibi, M. S., & Hosseinzadeh, H. Smartphone Addiction and Associated Health Outcomes in Adult Populations: A Systematic Review. International Journal of Environmental Research and Public Health (2021) 18(22). https://doi.org/10.3390/ijerph182212257

2. Materials and Methods

We described Table 1 in more detail including standard error (SE).

The reasons for choosing the 30s age group were added to the introduction as follows In lines 60-63.

“Previous analyses of Internet addiction among adults have primarily focused on adults in their 20s. Also, most analyses of smartphone addiction have focused on adults in their 20s (29,30); however, studies focusing on working adults over 30s are very limited.”

We considered that the Internet usage of working adults would differ from that of students who are not yet working, so we chose to focus our research on people in their 30s and older, the age at which they are working. We expected to find a different trend from those reported in the past for those in their teens and twenties. The 30s is an age in which differences occur between men and women in terms of life events and circumstances surrounding employment.

2.2. Measures

The question about Internet usage time and purpose of use is an original question by the author. The average daily Internet usage hours were interviewed separately on weekdays and holidays. The hours were rounded down after the decimal. SNS+ indicates those who used the Internet primarily for SNS, and SNS– those who used it for other purposes. The SNS type questions were asked which of "LINE," "Twitter," "Facebook," "Instagram."

The association between Internet usage time represented by time using SNS and sitting time for computer use, and depressive symptoms were added below in introduction.

In lines 54-58.

“There is a small positive correlation between time of using SNS and depressive symptoms (13). A relationship between time of using information devices and depression has also been noted. Multiple studies have reported that time spent sedentary using the Internet on a computer is positively correlated with depressive symptoms and anxiety (33).”

3. Results

Following your suggestion, we have added to the text and reference below in lines 154-155.

“The significances confirmed in the present samples are not always confirmed in other population (34)”

34. Ryder, A. G., Costa, P. T., & Bagby, R. M. Evaluation of the SCID-II Personality Disorder Traits for DSM-IV: Coherence, Discrimination, Relations With General Personality Traits, and Functional Impairment. Journal of Personality Disorders (2007), 21(6), 626–637. https://doi.org/10.1521/pedi.2007.21.6.626

SIGH-17 means the Hamilton Rating Scale for Depression (HRSD) in this study. We corrected the Table 2.

4. Discussion

We added a discussion citing the following article targeting adults in lines 202-212.

“Nakayama et al. reported that both weekday and holiday Internet usage time were risk factors for Internet addiction among Japanese students. The present study of an adult sample indicated that Internet usage time on holidays may represent more of a risk for Internet addiction, due to differences in lifestyle depending on the work situation (31).”

“Tsumura et al. warned of the risk of Internet addiction among adult school personnel. This report on working adults was analyzed separately for holidays and weekdays, and showed that individuals at risk for Internet addiction tended to spend significantly more time on the Internet on both weekdays and holidays. Tsumura et al.'s report confirms our current study, which targeted a more diverse range of occupations. Furthermore, our re-port is unique in that it discusses differences between weekdays and holidays. (32)“

31. Nakayama, H., Ueno, F., Mihara, S., Kitayuguchi, T., & Higuchi, S. Relationship between problematic Internet use and age at initial weekly Internet use. Journal of Behavioral Addictions (2020), 9(1), 129–139. https://doi.org/10.1556/2006.2020.00009
32. Tsumura, H., Kanda, H., Sugaya, N., Tsuboi, S., & Takahashi, K. Prevalence and Risk Factors of Internet Addiction Among Employed Adults in Japan. J Epidemiol (2018), 28(4), 202–206. https://doi.org/10.2188/jea.JE20160185

5. Conclusions

As you point out, with this small sample size, it is difficult to generalize the results. The sample size issue is shown as a limitation. To avoid misunderstanding, we have included "among the 129 working adult samples" in the Discussion and Conclusion.

We change “pathophysiology” into “mental health” in abstract and conclusion.

Author Response File: Author Response.pdf

Reviewer 4 Report

The study is relevant and interesting. In my opinion, the limitations of the study is the strongest part of the study. It is not necessary to include huge samples to come to reasonable conclusions. The authors may only strengthen their position, pointing out that depression and frustration are not the consequences of internet usage, but on the contrary, clinical pathologies may conduct to pathological use of internet. The use of Internet is related to the whole organization of the mode of life of each person. 

The authors should include some kind of theoretical introduction and conclusion to their study. It is also necessary to point out the necessity of clinical individual research in cases of any kind of pathology. Clinical studies might not be substituted  by general descriptive publications based on questionaries of the subjects.

Please, include the objectives  and ideas for your future studies. Please, include some kind of critical reflection in relation to general opinion about the danger of Internet use for young people. Please, include also some kind of practical recommendation in relation to the results.

Author Response

【Reviewer 4】

The study is relevant and interesting. In my opinion, the limitations of the study is the strongest part of the study. It is not necessary to include huge samples to come to reasonable conclusions. The authors may only strengthen their position, pointing out that depression and frustration are not the consequences of internet usage, but on the contrary, clinical pathologies may conduct to pathological use of internet. The use of Internet is related to the whole organization of the mode of life of each person.

The authors should include some kind of theoretical introduction and conclusion to their study. It is also necessary to point out the necessity of clinical individual research in cases of any kind of pathology. Clinical studies might not be substituted by general descriptive publications based on questionaries of the subjects.

Please, include the objectives and ideas for your future studies. Please, include some kind of critical reflection in relation to general opinion about the danger of Internet use for young people. Please, include also some kind of practical recommendation in relation to the results.

[Response]

We really appreciate you for your productive suggestions and comments regarding our manuscript.

The title was changed as below to clarify the target of our study, which focused on holiday Internet usage time. “Holiday Internet usage time and the risk of Internet addiction tendency among 30s working adults in Japan”

We change introduction and discussion for more theoretical meaning.

Following your suggestion, we have added to the text and cited surveys of the relationship between Internet and smartphone dependence among adults.

In lines 42-45.

“Differences in working status have been noted in the association between Internet usage time and compulsive Internet use among adults (31). A recent survey of working adults in Japan has indicated that groups at risk for Internet addiction tended to spend more time using the Internet (32).”

In lines 60-63.

“Previous analyses of Internet addiction among adults have primarily focused on adults in their 20s. Also, most analyses of smartphone addiction have focused on adults in their 20s (29,30); however, studies focusing on working adults over 30s are very limited.”

To make the clinical questions easier to understand, we have simplified the end of Introduction as follows.

In lines 65-67.

“We also hypothesized that Internet usage time on holidays, rather than on weekdays, would be more indicative of the psychological and psychosocial effects of Internet use.”

We added general opinion about the danger of Internet use for young people and practical recommendation in relation to the results in discussion part.

In lines 221-228.

“The pandemic of COVID-19 infection may have increased the risk of harmful Internet use in many regions of the world (35.36). A Japanese study including adults reported a 1. 5 times increase in problematic Internet use (PIU). The increase in Internet usage time after the pandemic was shown to be a possible risk factor for PIU. Online work is gradually increasing due to the diversity of work patterns, and Inter-net-related addictive behaviors will become more important as a working place mental health. The results of our study may indicate that monitoring internet usage on holidays is important for the maintenance of mental health in the workplace.”

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

congratulations for your work

Reviewer 3 Report

Thank you for considering the suggestions and making improvements to the manuscript.