Peer Review History

Original SubmissionDecember 4, 2019
Decision Letter - Geilson Lima Santana, Editor

PONE-D-19-33502

Risk factors for loneliness: The high relative importance of age versus other factors

PLOS ONE

Dear Dr. Dodell-Feder,

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Geilson Lima Santana, M.D., Ph.D.

Academic Editor

PLOS ONE

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Reviewer #1: Yes

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Reviewer #1: Yes

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Reviewer #1: Yes

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Reviewer #1: -This manuscript examined several risk factors for loneliness, including demographic characteristics, place (i.e., neighborhood), and their interaction. The study utilized a web-based survey and census data. As the structure of our social world is changing, loneliness is increasingly becoming a societal issue, predisposing individuals to various physical and mental health problems. This study is timely, well-structured and clearly written. I feel this paper contributes to the existing literature on loneliness.

-The review of past research on loneliness is comprehensive and informative. However, it remains unclear where the definition of loneliness (here “sadness due to the subject experience of feeling alone and/or social isolated”) is derived from. Please clarify the reference and consider including further definition of loneliness -maybe refer to a theory of loneliness?

-Overall, the analyses are carried out carefully. The methods chosen appear appropriate for the analyses and the data and screening tools used also appear to be fit for purpose. The authors also have recognized the limitations of the study as well as discuss possible future directions.

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Reviewer #1: No

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Revision 1

Journal Requirements

1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at http://www.plosone.org/attachments/PLOSOne_formatting_sample_main_body.pdf and http://www.plosone.org/attachments/PLOSOne_formatting_sample_title_authors_affiliations.pdf

Thank you for reminding us of PLOS ONE’s style requirements and providing examples. All revised documents are labeled according to PLOS ONE guidelines. Additionally, appropriate stylistic and formatting changes have been made and are reflected in the revised manuscript as follows:

• Superscripts to indicate author affiliations were changed from letters to numbers

• Asterisks to denote corresponding authorship were changed to come after superscript letters

• Corresponding authors’ initials were added in parentheses after email addresses

• Font size of Level 1 headings were changed to size 18

• Font size of Level 2 headings were changed to size 16

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• “Materials and Methods” section was changed to “Materials and methods” to reflect sentence case

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• The “Data Availability Statement” was removed from the Methods section. This identical statement is provided in the submission form.

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• Figure titles in captions for Tables 1-3 and Figs 1 and 2 were changed to bold type

• “This work was supported indirectly by a grant from National Institutes of Health to D.D.-F. (1L30MH117569-01)” was removed from the Acknowledgment section of the manuscript to not include any mentioning of funding sources

• “Supporting Information Captions” was changed to “Supporting information” to reflect sentence case and the unnecessary extra word

• The use of the word, “Figure” was changed to “Fig” in text citations and captions to reflect stylistic guidelines

2. You indicated that you had ethical approval for your study. In your Methods section, please ensure you have also stated whether you obtained consent from parents or guardians of the minors included in the study or whether the research ethics committee or IRB specifically waived the need for their consent.

That is correct, we do have approval from the Harvard University Committee on the Use of Human Subjects in Research (CUHS). More specifically, prior to completing any study measures participants provided informed consent/assent by electronically signing a form in a manner approved by the CUHS. Since the public nature of the research platform means that requirements of parental consent cannot be validated, and given concerns that any additional requirements related to age may lead to false self-reported age, the protocol was designed such that participants giving an age less than 18 were directed to measures that were deemed to be minimal risk for minors and otherwise not required to obtain parental consent (e.g., the measures used in the current study). This consent procedure has been in place since 2009 with no adverse events reported.

To address the editor’s comment, we provide this additional information in the revised manuscript as follows (p. 9):

“In addition to approving the study, given that the nature of the research platform cannot validate requirements of guardian consent, the Harvard University Committee on the Use of Human Subjects in Research (CUHS) waived the requirement of guardian consent for subjects who were minors at the time of study participation.”

Reviewer 1

This manuscript examined several risk factors for loneliness, including demographic characteristics, place (i.e., neighborhood), and their interaction. The study utilized a web-based survey and census data. As the structure of our social world is changing, loneliness is increasingly becoming a societal issue, predisposing individuals to various physical and mental health problems. This study is timely, well-structured and clearly written. I feel this paper contributes to the existing literature on loneliness.

We thank the Reviewer for their time and thoughtful comments below.

The review of past research on loneliness is comprehensive and informative. However, it remains unclear where the definition of loneliness (here “sadness due to the subject experience of feeling alone and/or social isolated”) is derived from. Please clarify the reference and consider including further definition of loneliness -maybe refer to a theory of loneliness?

We agree that this is an important point and we’re happy to have an opportunity to elaborate on the definition of loneliness and cite relevant work in the revised manuscript. We also appreciate your suggestion of placing loneliness within the context of a model of loneliness. In line with your suggestions, we cite the work of Paloutzian et al. (1982) when defining loneliness and describe a leading model of loneliness proposed by Cacioppo, Hawkley, and other colleagues (e.g., Cacioppo et al., 2006; Hawkley & Cacioppo, 2010). We have edited the first paragraph of the introduction accordingly as follows (p. 4):

This notion is perhaps best supported by the literature on loneliness, which is the feeling of distress caused by the perceived discrepancy between one’s desired and actual level of social relationships [1]. In other words, loneliness may be characterized as the social pain of perceived social isolation [2]. One leading model describes loneliness as a state of conflicting approach and avoidance social motivations to both connect with others and be on the look-out for social threats, all of which serve to put the lonely individual in a heightened state of social monitoring characterized by a negative self-reinforcing loop of biases in social attention and social memory, self-fulfilling prophecies, increased social distance, and feelings of social pessimism and low self-esteem [2-5]. Together, this process activates a variety of deleterious neurobiological mechanisms that negatively impacts health.

References

1. Paloutzian R, Ellison C, Peplau L, Perlman D. Loneliness, a sourcebook of current theory, research and therapy. 1982.

2. Cacioppo JT, Hawkley LC. Perceived social isolation and cognition. Trends in cognitive sciences. 2009;13(10):447-54.

3. Hawkley LC, Cacioppo JT. Loneliness matters: A theoretical and empirical review of consequences and mechanisms. Annals of behavioral medicine. 2010;40(2):218-27.

4. Layden EA, Cacioppo JT, Cacioppo S. Loneliness predicts a preference for larger interpersonal distance within intimate space. PloS one. 2018;13(9).

5. Cacioppo JT, Hawkley LC, Ernst JM, Burleson M, Berntson GG, Nouriani B, et al. Loneliness within a nomological net: An evolutionary perspective. Journal of research in personality. 2006;40(6):1054-85.

Attachments
Attachment
Submitted filename: Response to Reviewers .docx
Decision Letter - Geilson Lima Santana, Editor

Risk factors for loneliness: The high relative importance of age versus other factors

PONE-D-19-33502R1

Dear Dr. Dodell-Feder,

We are pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it complies with all outstanding technical requirements.

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With kind regards,

Geilson Lima Santana, M.D., Ph.D.

Academic Editor

PLOS ONE

Formally Accepted
Acceptance Letter - Geilson Lima Santana, Editor

PONE-D-19-33502R1

Risk factors for loneliness: The high relative importance of age versus other factors

Dear Dr. Dodell-Feder:

I am pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

If your institution or institutions have a press office, please notify them about your upcoming paper at this point, to enable them to help maximize its impact. If they will be preparing press materials for this manuscript, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org.

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With kind regards,

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on behalf of

Dr. Geilson Lima Santana

Academic Editor

PLOS ONE

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