The effects of cumulative stressful educational events on the mental health of doctoral students during the COVID-19 pandemic

GENERAL COMMENTS:

This is interesting research, but I am not sure why it was submitted to an environment-focused journal. I think the paper needs further development in places. The literature review and early set up is good, but connections to the research questions and frameworks that the authors draw from are less well organized. In several occasions throughout the introduction, the authors make broad statements without explaining and developing beyond declarative statements. I had several concerns about the sample and generalizability. The discussion might be better organized around main takeaways.

DETAILED COMMENTS:

Abstract: It is unclear what the sample is from this description. This would be helpful to add.

70-71: Why is it more meaningful to examine subpopulations separately? This also seems to suggest that your sample is representative of this subpopulation. And then what about examining subpopulations of PhD students separately?

71-73: What are your hypotheses as to why doctoral students are especially at risk?

122: This sentence repeats the last half of the previous sentence.

125-126: May help who offer better support? This is an example of greater specificity that is needed throughout. This is also repeated in lines 140-141.

127-129: This sentence belongs in one of the previous paragraphs as it relates more to ideas about cumulative stressors than the introduction of this study’s focus (this paragraph).

131: “Several factors” is overly broad. Describe these.

133-137: This framing is interesting and deserves more development. How does this framework relate to your research question? Do you analyze factors in this study broken down by these categories? Why don’t you? The turn from discussing these different factors to focusing on cumulative events is jarring and needs greater explanation in my read.

142-148: This introduction to the study could come earlier. The previous paragraph references a framework that breaks up categories of factors influencing mental health (macro, meso, micro), yet this paragraph then states that the focus of the study is on the effect of “cumulative stressful educational events.” Which is important? This shift to cumulative effects does not flow naturally from the discussion in the previous paragraph.

150-155: So macro, meso, micro distinctions are important. You might consider expanding more on these in the introduction, perhaps even using the framework as a way to organize the literature review. You might move the examples of macro, meso, micro factors up to where macro, meso, micro factors are first introduced. This discussion generally—and specifically the last sentence of this paragraph—need to better linked to research questions/ set-up. Why do we “explore the relationship of coping and attentional skills as factors that may promote good mental health?” You might restate the research questions that are being answered, and perhaps list or number the research questions somewhere in this introduction.

157-161: What country is the data from? Does “global study” mean from every country? Do variations in COVID-19 wave timing between countries affect your study? What about differences in PhD programs/ experiences? Why do you focus on the second wave? Because you anticipate that cumulative effects on PhD students will have had sufficient time to be noticeable? This makes sense, but it needs to be articulated, in my opinion. How were participants recruited? You reference a link to the study methodology, but more details in the paper text would leave fewer questions unanswered.

164: Any comment on the female-skewed sample? Any reason why the sample was skewed this way or hypothesizing as to how this may affect results? Also related to your sample, the group is largely not funded/ self-funded (77%). At least in the United States, this is not the norm. Why is this in your sample? How might this affect results?

168: Here is recruitment information. You might consider moving recruitment info before discussion of the sample obtained from recruitment.

202: This procedure of summing binary variables was unclear to me at first read. You might note in the previous sentence that these are yes/ no questions, as that was not obvious without looking at the table. How were these binary questions developed? Are questions 2-5 in this list supposed to be because of COVID-19?

216-220: You might consider adding equations for the three models.

222: These are descriptive statistics of only depression and anxiety variables so relabel the header as such.

275: Perhaps this difference in findings between your study and others is because of your skewed-female sample?

275-277: The discussion might be better organized around this, and other, main takeaways. In the following paragraph especially, discussion seems to jump from finding to finding.

295-296: You sum stressful educational events to create a measure of cumulative stressful educational events. If the CSEE measure is created by summing, what is “the sum of CSEE?”

300-302: This is a large limitation. It’s difficult to argue effects from COVID-19 without the pre-pandemic control/ difference-in-difference.

322: What percentages?

324: It is unclear what, “potentially given evidence for upskilling doctoral students with better coping skills” means. Are you arguing for training doctoral students to have better coping skills? What about assessing what subgroups are most affected by CSEE beyond what your sample can identify and more thoroughly hypothesizing and interrogating why? In terms of both upstream drivers and solutions, perhaps tie back to the macro, meso, and micro factors influencing stressful educational events and coping capacities?

Sideropoulos et al aimed to determine the effects of cumulative stressful events on the mental health of doctoral students during the COVID-19 pandemic. This research is important and under-explored; however, I am uncertain as to the appropriateness of the research for an environmental journal. While the research area is important, and the inclusion of assessment of coping skills and attentional ability is a strength, the manuscript could benefit from considerable revisions, with attention paid to setting up the research question, and presenting the results.

Specific comments:

Abstract:

Provide more information on the population/participants in which the study was conducted.

Introduction

Paragraph 2: provide examples/citations that support the claim that examining sub-populations separately is important.

Line 122: This sentence repeats what was stated in the previous sentence.

Methods

Line 181 is missing the close parenthesis.

On lines 183, 187, and 193, I would like to know more about how reliability was tested in more detail.

Section 2.2.4, I would imagine that factors that induce stress in the doctoral community differs by the specialization of study. For example, the nature/cause of stress of a PhD student in the humanities could be different from the factors inducing stress in someone from a “Professional Doctorate” degree. Is there is a reason the field of study was not included as a covariate?

Line 216, please provide more information on the data analysis.

Why were the two individual-level variables not investigated separately? Perhaps if there was more discussion of the relationship between the two variables in the introduction, this would become evident to the reader. As presented, it raises questions and the logic is not easy to follow.

Results

Line 240: Did the authors mean “covariates” instead of “covariance?”

Discussion

Line 251. The term “synthetic” confused me. Did the authors mean “systematic” way?

Line 322: What are the percentages?

The lack of consensus with previous research is unexpected and needs more discussion, likely in line with a lack of generalizability of the results given the unique sample and modest sample size.