Mr. Editor

In the article published by Baldeón-Martínez et al¹on depression in the elderly, the authors estimated a prevalence of depression of 14.2% in a probabilistic sample of 4917 people over 60 years of age in our country. Factors associated with this diagnosis were female sex, lack of education, age over 75, living in rural areas and being poor. This study was carried out on the basis of data from the 2017 Demographic and Family Health Survey (DHS), using the instrument Patient Health Questionnaire (PHQ-9) for the diagnosis of depression. The study presents some strengths such as the broad coverage, the quality of sampling and the detailed and up-to-date information on respondents, especially on socio-demographic aspects.

However, its analysis allows us to find a series of limitations and biases that the authors do not comment on in the discussion, such as: the methodology and objective of the study, the validity of the instrument used in the geriatric population and the relevance or redundancy of the research in relation to previously published works on the topic.

The specific objective of the DHS was not to estimate the prevalence rate of depression in the Peruvian elderly, being the information of the article obtained from a secondary database. On the other hand, the authors mention as an objective to determine the variables associated with geriatric depression, using the formula of sample size of frequencies used by the DHS and not one of the risk factors, which would be most appropriate and would allow a correct interpretation of the Odds Ratio (OR) obtained.

The instrument used was the PHQ-9 validated in Peru by a committee of mental health experts, but as Calderón et al², mentioned in their 2012 article, validation had not been done in the population, where there could be socio-cultural differences between coastal, highlands and jungle communities. As the instrument supplemented by self-report, the authors do not mention the criteria for exclusion from their study, such as chronic cognitive impairment, delirium, hearing loss, decreased visual acuity, locomotor system disorder or language barrier, all common conditions in elderly³.

Recent revisions on the instruments used in the diagnosis of depression in the elderly, agree that the Geriatric Depression Scale (GDS) or Yesavage Scale and the Center for Epidemiological Studies-Depression Scale (CES-D) are the most reliable instruments for their use, taking into account specific aspects of the presentation of this pathology in this age group, such as attention deficit and memory deficit, somatizations, anxiety and sleep disorder⁴. In fact, in the discussion of their work, the authors compare their findings with those obtained in studies using these instruments.

Finally, the study does not show greater relevance and is even redundant compared to what was published by Martina et al⁵, who examine depression and associated factors in the Peruvian elderly population according to DHS 2014-2015, finding a prevalence of depression of 14.3% and association with factors such as the female sex, being over 75 years old, lack of education, living without a partner, living in rural areas, poverty and physical disability.

We believe that there is a need for more population studies on the subject, addressing depression in the elderly as a disease, with a focus not only on social and demographic, but also on medicine. One proposal could be to study the groups identified as high-risk, along with a comprehensive geriatric assessment, which would allow for timely intervention spaces⁶.