The article on Descriptive Epidemiology of Undetected Depression in Institutionalized Older People by Damian, Pastor-Barriouso, and Valderrama-Gamma (2010) is a cross-sectional study conducted in Madrid (Spain). The goal of the study was to determine the proportion of unidentified depression in older people who stay at aged care institutions. The study design was cross-sectional. The researchers used the probability-sampling method to select the institutions that were included in the study. The private, as well as public nursing homes in Spain and their environs, were included in the study. A stratified cluster sampling method was used to select the participants. The sample consisted of old people who were more than sixty-five years. The ratio of women to men was 50:50. The exclusion criteria were older people who were more than sixty-five years but had not stayed in the nursing homes for more than sixty days, patients with severe cognitive abnormalities, and those who could not define the term depression. Therefore, the sample population was five hundred and seventy-nine old people. The researchers collected data via interviews and review of health records. The health care professionals working in the nursing homes were interviewed to ascertain the diagnosis of depression as well as the prescriptions of the medications. The old people were interviewed using a depression scale. If the participant had a score of more than four, a diagnosis of depression, and a prescription, he was considered to be depressed. Stata Statistical Software analyzed the data. The estimation of occurrence of depression was via a confidence interval of ninety-five percent through the social, demographic, and health status of the participants. The researchers found that one hundred and eight old people had depression yet they were undetected. The rate of health care professionals not detecting depression was low in patients who had not stayed for a longer period, private institutions, and big facilities. On the other hand, it was high in anxious patients, with Alzheimer’s disease and dysrhythmias. The cause of the high prevalence of undetected depression was the medications that the patient was taking and his health status. The limitation of the study was that the researchers did not use DSM-IV criteria to diagnose depression but instead used a depression scale. This increased the probability of misclassification. Secondly, the researchers relied on the report of the patient to diagnose depression. Thirdly, old people with severe cognitive disorders were not included in the study yet their counterparts with mild impairment took part in the research. Lastly, the incidence of depression could have interfered with the results. The article on Biopsychosocial factors related to depression in aged care residents by Davinson, McCabe, Knight, and Mellor (2012) is a cross-sectional study conducted in metropolitan Melbourne. The goal of the study was to explore the relationship that existed between depression in older people living in nursing homes and biopsychosocial factors. The study design was cross-sectional research. The sample consisted of one hundred old people living in