Depression, Loneliness and Quality of Life in Institutionalised and Non-Institutionalised Older Adults in Portugal: A Cross-Sectional Study

Comments 1: I suggest enriching the introduction with studies from outside the COVID-19 pandemic period, particularly those concerning institutionalization/socialization and depression/quality of life.

Response 1: Thank you very much for your suggestion. We've added studies in line with the comment to make the introduction more robust. The changes are on lines 129-144: “Institutionalisation and socialisation play crucial roles in the mental health and quality of life of vulnerable populations, particularly older adults. Institutionalised older adults have a higher prevalence of depressive symptoms, with a significant negative correlation between depressive symptoms and physical quality of life (32,33). Developing interventions that promote socialisation can lead to better health outcomes and a better perception of quality of life (34). So, we might think that in the population of institutionalised older adults it could be very useful to promote socialisation, as this can lead to improvements in various dimensions (33,35).

In fact, from a mental health prevention and promotion perspective, promoting socialisation in institutional settings can reduce the risk of developing depressive symptoms and improve quality of life among institutionalised people. In addition, internal and ex-ternal social support plays a crucial role in predicting the quality of life of institutionalised older adults, with a strong association found between social support and quality of life, i.e. social support can be considered a predictor of quality of life in institutionalised older adults (36).”

Comments 2: Include a theoretical framework that supports the transition process, for example, of ageing.

Response 2: Thank you very much for your proposal. In fact, including studies that frame the ageing process is important. We've added a few studies. The changes are on lines 47-72 “The phenomenon of ageing is the natural, progressive, dynamic and irreversible pro-cess that people go through over time, accompanying them throughout their lives, from birth to death, emerging physical, biological, social, economic, cultural, environmental, historical and psychological changes that occur in the person. This process is observed in all forms of life and is an intrinsic part of the life cycle of all organisms, including humans (1–3).

In the human context, ageing is characterized by a series of changes that can vary from person to person, but some common changes include physical changes such as changes in skin, hair, nails, vision, hearing, muscle capacity and bone density. A decline in cognitive function can also occur, where people can experience difficulties with memory, concentration and the speed at which they process information. There can be an increased susceptibility to disease, as with ageing the immune system can become less efficient, making the body more vulnerable to infections and illnesses. Changes in the emotional dimension can also arise, as older people may face emotional challenges, such as dealing with personal losses and facing issues related to mortality. Ageing can also in-volve changes in social relationships, such as retirement and the establishment of new family roles (1,2,4,5).

Although ageing is inevitable, there are measures people can take to promote healthy ageing and improve their quality of life as they get older. These can include a balanced di-et, regular exercise, activities that stimulate the mind and participation in a social support network. It's important to recognize that ageing can also be a time of opportunity and personal growth. Society can benefit from the contribution of older people, as they have experience, wisdom and knowledge accumulated throughout their lives (2,5). It is there-fore essential to respect and value people as they age and to ensure that they have access to adequate resources and care to enjoy a full and meaningful life throughout their existence.”.

Comments 3: Add a research question.

Response 3: Thank you very much for the alert. We've added a research question. The changes are on lines 148-150: “Hypothesis 1 (H1). There is a significant correlation between depressive symptomatology in institutionalised and non-institutionalised older adults and their levels of negative feelings of loneliness and perceived quality of life.”

Comments 4: Why was the age set at 60 years? The WHO states that an elderly person is 65 years old or older.

Response 4: Thank you for your very pertinent comment. Several studies have used age over 60 as a reference for older adults, which is why we opted for this criterion. If the manuscript is accepted for publication, it may have the potential to be cited if other studies from other countries are interested in comparing results.

It was a methodological choice by the authors, but we admit that it may be debatable.

Comments 5: Should severe cognitive impairments not be an exclusion criterion?

Response 5: Thank you very much for the warning. Yes, cognitive impairment should indeed be included as an exclusion criterion, and it was considered, being an important factor in reducing the study's bias. Our sampling method was one of convenience, so it was assumed that the participants who were referred to us by health professionals from the institutions did not have cognitive impairment, as this was our indication. We have clarified this in the exclusion criteria and in section. The changes are on line 162: “as well as participants with cognitive impairment, to reduce study bias.”.

Comments 6: What was the reason for 7 participants not completing the PHQ-9?

Response 6: Thank you very much for your comment. The reason was simply that the participants didn't want to take part in the study. It was therefore not possible to collect this instrument. We have clarified this in the manuscript. The changes are on lines 169-171: “,and 7 could not be given the PHQ-9 instrument (due to participants giving up on taking part in the study, and so it was not possible to harvest this instrument).”

Comments 7: In what period was the study conducted?

Response 7: Thank you very much for the warning. We've clarified this in the manuscript. The changes are on lines 171-172: “The study lasted four months, from September to December 2023”.

Comments 8: How were the data collected, in person? Who collected the data? The research team?

Response 8: Thank you very much for the warning. It's important to clarify. We've added this information to the manuscript. The changes are on line 172: “The participants filled in the instruments in the presence of the researcher”.

Comment 9: The colours of the graphs are difficult to read.

Response 9: Thank you very much for your comment. We've remodelled the “Figure 2. Prevalence of depressive symptoms assessed by the Patient Health Question-naire-9 (PHQ-9), according to institutionalization status.”. The changes are on lines 292-293.

Comment 10: Enrich the discussion with reflections on:

The sociodemographic characteristics, and whether they are in line with national and international data.

Response 10: Thank you very much for your comment. We've added some discussion to the manuscript. The changes are on lines 316-322: “In Portugal, institutionalised older adults tend to be mainly women with multimorbidity (46), which is in line with our study, since women in Portugal have a longer life expectancy than men, and due to age, multimorbidity is common. Overall, institutionalised older adults are more likely to be single (47) because if they are married, they may have some support from their spouse, and with an average age of 84 (46), because at older ages they are more likely to need the support of institutionalisation, which is also in line with our study.”.

Comment 11: Why are there more depressive symptoms and loneliness among institutionalized elderly?

Response 11: Thank you very much for your comment. We've added some discussion to the manuscript. The changes are on lines 339-344: “This may be due to the fact that institutionalisation can lead to a decrease in the frequency with which older adults socialise with friends and family, it can lead to a change of place of residence with a whole new set of routines that alter the daily life that the older adult was used to, it can lead to moving away from the city they have lived in for many years and less participation in leisure activities.”

Comment 12: What are the psychotherapeutic interventions that reduce depressive symptoms in the elderly?

Response 12: Thank you very much for your comment. We've added some discussion to the manuscript. The changes are on lines 465-472: “The development with older adults of psychotherapeutic interventions such as psychotherapy, cognitive-behavioural therapy, behavioural therapy and reminiscence therapy can be very useful in reducing depressive symptoms in older adults living in different environments, including those living in long-term care institutions (76,77). Research into interpersonal psychotherapy also emphasises its effectiveness in reducing depressive symptoms and preventing relapses in depressed patients, and also shows its effectiveness as a good intervention option for older adults with depressive symptoms, as reported in a recent Randomised Control Trial (78).”.

Comment 13: What is the relevance of the results for the competencies of specialist nurses in mental health nursing?

Response 13: Thank you very much for your comment. We've added some discussion to the manuscript. The changes are on lines 488-494: “These results are relevant to the competences of nurses specializing in mental health nursing, as they can provide quality and safe care centred on the person and the family, including risk assessment and management, understanding the principles of recovery, communication skills, knowledge about mental disorders and their treatment, research evaluation and the promotion of physical and mental health. And in this sense, they can develop a range of interventions with older adults in pursuit of these competences, they are trained to do so.”.

Comment 14: What is the relevance of this study for clinical practice, education, and research?

Response 14: Thank you very much for the alert. This is indeed an important reference. In conclusion, we emphasise the relevance of this study for clinical practice, teaching and research. The changes are on lines 502-510: “The results of this study are relevant to clinical practice, teaching and research. Firstly, in terms of clinical practice, the results of this study could lead to an improvement in the quality and safety of care provided to older adults, as it highlights the need to intervene with the aim of reducing depressive symptoms, reducing negative feelings of loneliness and improving quality of life. In terms of teaching, the results of this study can be used to increase their analysis and discussion to promote students' critical thinking and thus prepare them to make informed decisions based on scientific evidence. In terms of research, the results of this study could lead to the development of new approaches to advance scientific knowledge.

Comment 15: Future recommendations?

Response 15: Thank you very much for your comment. We have added future recommendations in the conclusion. The changes are on lines 523-524: “We recommend similar studies in the future with a more equal sample of male and female participants and a more balanced age distribution”.

Comment 16: Review references number 15, 20, 45, and 57.

Response 16: Thank you very much for the very pertinent warning. It was a misinterpretation. We've removed the references.

4. Response to Comments on the Quality of English Language

Point 1: The English of the article is of good quality.

Response 1: We revised the language of the entire manuscript with the aim of improving the English.  (in red)

5. Additional clarifications

We believe that we have responded to Reviewer 1's requests, and we are available to continue improving the manuscript if necessary.

Comments 1: The initial introduction discusses ageing straight away, please briefly introduce the depression, loneliness and QOL briefly, then discuss the fundamentals of ageing issues. We don't particularly want to see ageing as the issue rather the factor mentioned in the ageing process. The introduction is well-written, well-synthesized with a clear focus. However, the initial opening sentence should quickly relate to the broad topic of the study, without exploring the process of ageing.

Response 1: Thank you very much for your pertinent comment. We've added some background at the beginning of the introduction that we think responds to your alert. If you need any further clarification, please let us know. Lines 47-59.

Comments 2: Although mentioned in the selection process, please provided a minor/brief acknowledgement of institutionalized vs non-institutionalized environments accounted for. Line 94-96.

Response 2: Thank you very much for your comment. We've added some text in response to your comment. Lines 109-115.