Prevalence and Correlates of Probable Depression and Anxiety Among Homeless Individuals During the COVID-19 Pandemic in Germany

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript addresses a topic of clear relevance to public health research. While the theme of the pandemic has already been widely explored in the literature, the identification of risk factors among vulnerable populations remains particularly important in order to prevent adverse outcomes in future pandemics.

The study design is appropriate, and the results are clearly presented. However, the discussion would benefit from further exploration of the proportion of individuals within the homeless population who report never having used alcohol and/or drugs and who do not present mental health problems, as this finding may offer important insights for public health interventions.

Author Response

We would like to thank the reviewer very much for the thorough, thoughtful, and positive evaluation of our manuscript. We greatly appreciate the time and effort invested in reviewing our work and are pleased to respond to the comment below.                                                                                 

Comment:

However, the discussion would benefit from further exploration of the proportion of individuals within the homeless population who report never having used alcohol and/or drugs and who do not present mental health problems.

Response:

We thank reviewer for the positive evaluation of our work and for this valuable suggestion. In response, we have added a paragraph to the discussion addressing the heterogeneity of the homeless population.

Change implemented: Discussion, Section 4.1, lines 302-306.

Once again, we sincerely thank the Editor and all Reviewers for their insightful comments, positive feedback, and the opportunity to improve our manuscript.

Reviewer 2 Report

Comments and Suggestions for Authors Dear Authors, The research is good; it sheds light on a marginalized group in society and focuses on their psychological suffering. The introduction is appropriate and well-documented. The methods followed the appropriate scientific methodology. The tools used probe symptoms of depression and anxiety; therefore, it is more appropriate to say "prevalence of symptoms of depression and anxiety." The authors did not mention the sampling method; was it random? How was the sample size determined? A crucial question: why the delay in publishing this manuscript until now? The discussion is appropriate. The number of references is good, but there are no references from the last two years.      

Author Response

We would like to thank the reviewer very much for the thorough, thoughtful, and positive evaluation of our manuscript. We greatly appreciate the time and effort invested in reviewing our work and are pleased to respond to the comment below.

Comment 1:

The tools used probe symptoms of depression and anxiety; therefore, it is more appropriate to say “prevalence of symptoms of depression and anxiety.”

Response:

We thank the reviewer for the careful reading of the manuscript and for this important methodological comment. We acknowledge that the PHQ-9 and GAD-2 assess symptoms rather than providing clinical diagnoses. However, throughout the manuscript we consistently use the terms “probable depression” and “probable anxiety”, which are widely accepted in epidemiological research using validated screening instruments with established cut-offs. This terminology establishes comparability with previous population-based and homelessness research. We therefore respectfully decided to retain the original wording.

Comment 2:

The authors did not mention the sampling method; was it random? How was the sample size determined?

Response:

We thank the reviewer for this comment and for acknowledging the overall quality of the manuscript. We have clarified the sampling procedure in the methods section, stating that a convenience sample was used.

Change implemented: Methods, Section 2.1 (Sample), lines 104-105.

Comment 3:

A crucial question: why the delay in publishing this manuscript until now?

Response:

We thank the reviewer for raising this important point. The timeline reflects the time required to process and analyse the large and diverse NAPSHI dataset, including parallel analyses of multiple outcomes. The manuscript was promptly submitted after completion and remained under editorial consideration for an extended period of time. When invited to contribute to this special issue, which provided an excellent fit, we withdrew the manuscript to submit it here. We are very pleased with the fast and positive evaluation of our work and believe the findings of this paper remain highly relevant, as the mental health burden in this marginalised population is likely to persist.

Comment 4:

The number of references is good, but there are no references from the last two years.

Response:

We thank the reviewer for this observation and for the overall positive assessment of the reference base. We agree with the reviewer and thus screened and edited publications from the past 2 years. Fortunately, the previously cited literature remains highly relevant for the interpretation of our findings.

Change implemented: Introduction, Section 1, line 63; Discussion, Section 4.1, lines 307-311

Once again, we sincerely thank the Editor and all Reviewers for their insightful comments, positive feedback, and the opportunity to improve our manuscript.

Reviewer 3 Report

Comments and Suggestions for Authors

The study is both interesting and relevant, and it appears to be part of a larger project.
In lines 41–42, the authors state that the study design includes clinical, laboratory, and questionnaire-based components. However, the results section does not present any clinical or laboratory findings. If this manuscript intends to focus solely on the questionnaire-based component, the study design should be described as a questionnaire-based cross-sectional study.

In line 111, the authors mention that blood samples were taken after the interview, but the purpose of collecting these samples and the corresponding results are not clearly explained.

Additionally, an asterisk should be added in Table 1 to highlight the associated factors.

The tables are clear and easy to interpret, and the discussion is well-articulated. The conclusion is also adequate.

Author Response

We would like to thank the reviewer very much for the thorough, thoughtful, and positive evaluation of our manuscript. We greatly appreciate the time and effort invested in reviewing our work and are pleased to respond to the comment below.

Comment 1:

The study design includes clinical, laboratory, and questionnaire-based components, but only questionnaire data are presented. The purpose of collecting blood samples is not clearly explained.

Response:

We thank reviewer for this important clarification and for the positive appraisal of the study design. We have revised the description of the study design to clearly state that the present manuscript focuses exclusively on questionnaire-based data. We further clarified that clinical examinations and blood samples were collected for parallel analyses reported elsewhere.

Change implemented: Methods, Section 2.1 (Sample), lines 109-110.

Comment 2:

An asterisk should be added in Table 1 to highlight associated factors.

Response:

We thank the reviewer for this helpful suggestion. We have revised Table 1 by adding an asterisk to variables that were significantly associated with the respective outcomes in univariable analyses (p < 0.05). A corresponding explanatory footnote has been added in the table legend.

Change implemented: Results, Table 1 and table legend.

Once again, we sincerely thank the Editor and all Reviewers for their insightful comments, positive feedback, and the opportunity to improve our manuscript.

Reviewer 4 Report

Comments and Suggestions for Authors

The idea for the analysis regarding the probable depression and anxiety with the correlation for homelessness and COVID is very interesting. The manuscript is well written, and the analysis is well done as well. My minor suggestion is to elaborate more on the clinical diagnosis of both depression and anxiety, explain a little more why the clinical scales (PHQ-9 and GAD-2) are important, and how they correlate with the clinical phenomenology of those two conditions.

Author Response

We would like to thank the reviewer very much for the thorough, thoughtful, and positive evaluation of our manuscript. We greatly appreciate the time and effort invested in reviewing our work and are pleased to respond to the comment below.

Comment:

Please elaborate more on the clinical diagnosis of depression and anxiety and explain why the clinical scales (PHQ-9 and GAD-2) are important.

Response:

We thank reviewer for the positive feedback and this constructive suggestion. We have added an explanatory paragraph in Section 2.2 specifying the PHQ-9 and GAD-2 and their role in clinical use.

Change implemented: Methods, Section 2.2 (Dependent Variables), lines 118-122.

Once again, we sincerely thank the Editor and all Reviewers for their insightful comments, positive feedback, and the opportunity to improve our manuscript.