Untreated Depressive Symptoms Signi cantly Worsen Quality of Life of the Elderly and may Lead to the Misdiagnosis of Dementia: A Cross-Sectional Study

Viktor Voros (  voros.viktor@pte.hu ) University of Pecs https://orcid.org/0000-0003-4836-4789 Sandor Fekete Department of Psychiatry and Psychotherapy, University of Pecs Tamas Tenyi Department of Psychiatry and Psychotherapy, University of Pecs Zoltan Rihmer Department of Psychiatry and Psychotherapy, Semmelweis University and National Institute of Psychiatry and Addictions Ilona Szili Department of Clinical Psychology, Karoli Gaspar University of Reformed Church Peter Osvath Department of Psychiatry and Psychotherapy, University of Pecs


Background
In our aging society, not only the maintenance of health of the elderly, but also the restoration of their quality of life (QoL) has become an important goal. Therefore, many studies aimed to detect factors in uencing QoL, as those may have preventive and therapeutic signi cance. Several studies have demonstrated the role of depressive disorders and cognitive impairment in the background of elevated mortality and decreasing QoL of the elderly [1][2][3][4].
The close correlation between depression and dementia is well-known however, the link between them is still unclear, and a subject of intensive research. According to a recent meta-analysis, depression in elderly can be an important risk factor for several types of dementia [5]. Furthermore, it was suggested that the same risk factors may be present in the background of dementia and depression in elderly, or even the same pathophysiological impairments may lead to both conditions [6][7][8]. Based on these ndings, depression may be an early marker of mild cognitive impairment and incipient dementia [9].
Furthermore, depression and dementia are also stressed as one of the most important risk factors for suicide in elderly [10].
Based on the above, we investigated depressive symptoms, cognitive functions and QoL of the elderly population, and we also assessed the occurrence of the diagnosed and treated mental disorders and psychotropic medications. The primary aim of our study was to evaluate the frequency of depressive and cognitive symptoms among elderly, and to investigate whether those are recognized and adequately treated or not. In addition, we also investigated which psychopathological symptom affect their QoL to the most extent. Based on the literature, our hypothesis was that in many cases cognitive decline and mood disorders are not recognized and treated, and these both negatively affect the QoL of the elderly [11,12]. The signi cance of our research is emphasized by the fact that the early detection and adequate management of affective symptoms in elderly may contribute to the improvement of mental disorders and their QoL.

Methods
In the framework of the ICT4Life project, self-administered questionnaires and clinical screening tools were used to assess QoL, depressive symptoms and cognitive functions of 60 elderly (47 females and l3 males) over the age of 65, who lived independently in their own apartments and participated in the elderly club of the Integrated Daily Social Institution in Pecs, Hungary [13]. Participation was voluntary and anonymous following the signature of the informed consent form (ICF). The study was approved by the local Ethics Committee.
Two tests were used to assess QoL of the elderly, the abbreviated version of the Older People Quality of Life (OPQOL-Brief) and the Quality of Life in Alzheimer's Disease (QOL-AD) questionnaires. The former is a 13-items short version of the well-known QoL scale (OPQOL-35), which has bene cial psychometric properties [14]. The QOL-AD questionnaire was speci cally developed to assess the QoL of people with dementia, especially Alzheimer's disease. It is based on a semi-structured interview, in which 13 items regarding QoL are covered. Evaluation of the questions is based on a four-grades Likert scale ranging from bad to excellent [15]. The Mini-Mental State Examiner (MMSE) was used to evaluate the cognitive levels of the elderly. The total score is 30 points with a 24 points of cut-off score for dementia [16]. Depressive symptoms and the severity of depression was measured by the 15-items Geriatric Depression Scale (GDS) [17]. The short version of the GDS can be easily applied to patients even with mild or moderate cognitive decline as well; and is considered to be a useful tool to differentiate depressed elderly from the non-depressed ones [18].
We also assessed the socio-demographic characteristics, the physical and mental disorders, and medication usage with semi-structured interviews. The review of medical records was also completed in order to control data captured during the semi-structured interviews.
The data was analysed by using SPSS 20.0. We performed descriptive statistical analyses, χ2-probe and Mantel-Haenszel test were used to identify group differences, and ANOVA for comparison of mean values.

Results
Regarding gender differences, the mean age of men was lower than that of women (74.08 vs. 77.96 years). Common diseases (such as hypertension, rheumatological problems, cardiac diseases, arteriosclerosis, etc.) characterized a signi cant proportion of both elderly males and females, as did other physical comorbidities. Both women and men took a number of medications because of their several illnesses. In addition to medications taken for the underlying physical conditions, the use of analgesics and psychotropic medications was also signi cant (Table 1.). Males had more previous (46.2% vs. 36.2%) and current (30.8% vs. 23.4%) psychiatric treatments. However, no signi cant gender differences were found in the occurrence of the already diagnosed mental disorders, in the number of previous in-patient or out-patient psychiatric treatments, or in the current use of psychiatric medications (Table 1.). Among mental disorders in the patients' history, addictions were more common among males (15.4% vs. 0%), while depression (21.3% vs. 15.4%) and dementia (21.3% vs. 7.7%) in females. ). In the group of elderly screened to be positive for depression, the mean scores of the cognitive (MMSE) and the QoL scales were signi cantly lower (Table 3.).

Discussion
As limitations of the study, rst we highlight the low number of cases and the fact that only those elderly took part in the assessments, who signed the ICF, and whose mental and physical condition was good enough to be able to consent and complete the questionnaires and screening tests. However, our results can be considered representative of this population living independently in their own apartments and has contact with the elderly club. Furthermore, the primary purpose of using clinical screening tools was to assess depressive or cognitive symptoms. These tools cannot be used to clinically diagnose depression or dementia. Therefore, the nding of signi cant proportion of depressive symptoms does not necessarily mean that these elderly suffered from clinical major depressive disorder (MDD). However, it is important to highlight that although elderly were in regular contact with health care systems due to their physical illnesses, depressive symptoms were mostly unrecognized, thus speci c psychiatric assessment and adequate treatment could not be performed. Lastly, the use of structured clinical interview may be of limited value in elderly because of the frequent occurrence of cognitive decline. Therefore, extensive review of medical records was also completed.
About half of the elderly took some psychotropic medications, and the same proportion had cognitive impairment reaching the level of dementia (mainly mild, according to the MMSE), and a little less (but more than 40%) found to be depressed by the GDS depression screening tool (Table 1.). Although it was somewhat more common to take antidepressant medications, there was a greater proportion of current depressive symptoms among males. No other major differences were found between genders.
In the elderly sample, out of the 11 patients taking antidepressants 6 patients received adequate antidepressant therapy and were without current depressive symptoms, which may indicate the e cacy of the antidepressant treatment in this elderly population (Table 2.). 26 elderly had current depressive symptoms, but only 9 of them contacted with a psychiatrist, and 7 of them had a clinical diagnosis of depression. Furthermore, only 5 of them received antidepressant medication (which also means that 21 elderly was found to have depressive symptoms, but their depression was not treated), but still they had some depressive symptoms. On the other hand, these patients with current depressive symptoms were more likely to receive antipsychotic medications. This indicates that only certain symptoms of the depressive disorder (sleep disturbance, anxiety, agitation) have been observed and treated (with antipsychotics), while the underlying mood disorder was not considered, and therefore the adequate treatment (antidepressant) was lacking. Theoretically, antipsychotics, especially rst-generation ones may be associated with the occurrence of depressive symptoms, but it is unlikely, as all the patients treated with antipsychotics were treated with a second-generation antipsychotic, which rarely induce depressive symptoms. Moreover, as it is known from the literature and clinical practice, some secondgeneration antipsychotics may even improve depressive symptoms or can work as antidepressants [19]. So, these antipsychotics might be prescribed to treat depression in the elderly. Although, for many patients there was only partial response to these antipsychotic or antidepressant medications, as -at least some of the -depressive symptoms were still present.
Based on our analysis, among elderly with current depression (according to the GDS) cognitive decline (assessed with the MMSE) was signi cantly more frequent and more pronounced, but this was not recognized and treated. In line with previous literature data, the results of this study showed that depressed (according to the GDS) elderly had lower cognitive levels and their QoL was also signi cantly poorer than that of the non-depressed (Table 2, 3.). Our results con rm close correlation between depression and cognitive impairment, as well as the key role of depression in the background of QoL decline [3,20,21]. On the other hand, it is well-known that reversible depression-related cognitive decline (also known as depressive pseudo-dementia) is often considered as true dementia and these patients do not receive adequate treatment for their mood disorder [22]. However, the depressive pseudo-dementia in old age seems to be a long-term predictor of true dementia [5,23].