Suspicion of the presence of non-psychotic symptoms
The main non-psychotic mental disorders in the elderly are anxiety disorders [
20]. These disorders reduce function and quality of life and may increase risk for other diseases such as depression, dementia, and cardiovascular disease [
21]. The prevalence of anxiety disorders in older adults varies according to studies. In the article by Mackenzie et al., in the large NESARC study that included over 12,000 adults aged 55 and older, the frequency of these disorders was 2.8% [
22]. Similarly, the article by Grenier et al., in a large epidemiologic study of older adults in Quebec, found that the combined incidence of syndromal and subthreshold anxiety was 26.2% [
23]. In the study by Kirmizioglu et al. [
24], prevalence for all types of anxiety disorders was 17.1%.
There are relatively few data on the prevalence of personality disorders in the elderly people. The aging advances might be expected to decline the frequency of personality disorders such as aggression, impulsivity, etc. However, co-occurring mental problems can increase their severity, for example older people are often socially withdrawn due to depressive disorders [
25]. The incidence of personality disorders among older adults has been estimated to be about 10% [
26‐
28]. The frequency of one or more personality disorders in the elderly in late-life are from 3 to 13% [
29]. In addition, personality disorders were related with disability as well as somatic and mental disorders [
30].
In our study, the median of total GHQ point value indicated a suspicion of the presence of non-psychotic mental symptoms, but the prevalence of non-psychotic symptoms was slightly lower than previously reported in other studies. Overall GHQ-28 result was higher for women than for men. A similar relationship and results were found in the study involving the Dutch population [
31] and in the study by Apidechkul [
32]. The results of the studies carried out by Kilic et al. [
33] showed higher GHQ results for women than for men.
Zare et al. [
34] showed a significant difference between the mean overall result and the mean results of GHQ-28 subscales among respondents. In that study, older adults were characterized by worse health status than other respondents [
34]. In the study by Momeni and Karimi [
35], the overall GHQ result and the results of the subscale of social dysfunction were almost identical to the results in our study, but there were certain differences in comparison with the other subscales. A medical history of chronic diseases in older adults was correlated with symptoms of anxiety and depression reported in other studies [
36,
37]. The occurrence of advanced depression ranged from 1% to 16% in older adults in private homes or institutions [
38], which is close to the results reported in our study.
The data indicated a higher prevalence of depressive symptoms in nursing homes residents, or even clinically relevant depression, which may also be related to age. Thus, the results confirmed our hypothesis that the studied disorders occur most frequently in residents of nursing homes. Nordtug et al. [
39] carried out an interesting study, showing that mean GHQ-28 scale results were lower for patients with chronic obstructive pulmonary disease than for patients with dementia. Krzych et al. [
40] presented similar results in a study conducted on cardio-surgical patients with an average age of 71. Makowska and Merecz [
41] reported even better results in an assessment of mental state in their study. The GHQ questionnaire also showed mental and social disorders in patients with backache in the study of Iranian women [
42] and in the Greek studies carried out in primary health care facilities [
43]. Our results, compared with the results of other authors, confirmed the hypothesis that mental disorders are an important health and social problem in the studied group of seniors.
In our study, women had higher mean results in terms of the abovementioned features, however, the difference was not meaningful or statistically significant. In the study by Datta et al. [
44], a model of multiple linear regression showed no significant relationship between the respondents’ sex and the total GHQ result and the results of the subscales of somatic symptoms, social dysfunctions, and advanced depression. However, women had significantly higher results for anxiety and sleeping disorders [
44]. The predominance of women in subscales assessing anxiety and sleeping disorders may be related to the fact that the number of older women is bigger than men in many countries in the world, and the level of ensured social security is lower. In the study by Cabak et al. [
45], patients with backache showed a much lower level of well-being in terms of mental health than respondents from the control group. Comparable differences were noted in the case of both women and men with chronic pain. However, in this case, men were more prone to depression.
Occurrence of depressive symptoms
After dementia, depression is the second most frequently occurring psychopathological syndrome in older adults; dementia and depression belong to so-called geriatric giants (next to, e.g., falls, mobility disorders, urinary and fecal incontinence, impaired hearing and seeing) [
46]. Compared with the younger population, depression in older adults is characterized by more differentiated and complex etiology and specifics of the clinical presentation, with frequent co-occurrence of somatic symptoms. Depressive disorders in older adults are often chronic and may greatly affect the quality of their health and life. Not only are they the cause of suffering in older adults, impairing their functioning and life quality, they are also accompanied by other diseases, consequently increasing mortality [
47‐
49].
Overall prevalence of depressive symptoms in our study group was around 18%. Results from the literature showed that the prevalence of depression in the world varied from study to study. In China, the prevalence of depression was 3.86% [
50]. The incidence of depressive symptoms among older adults in Bangladesh was 45% [
51]. The frequency of depressive symptoms in older adults in Turkey was 38.7% [
52]. Differences in the sampling of subjects could have resulted in the observed differences in depression prevalence in the elderly in these studies. Compared with the results from the Turkish study [
52], including people aged 60+, our prevalence is lower, which could be related to the volunteer group in our study. Summing up, the prevalence and risk of depression in our study were lower than the results of other studies, such as by Jo et al. [
53]. Their results differed from the results of studies conducted on younger adults in Korea [
54]. A meta-analysis of studies of people over the age of 75 indicated that the incidence of major depression to be 7.2%. Values for women ranged from 4.0% to 10.3% and for men from 2.8% to 6.9% [
55]. The frequency of major depression is estimated to be between 10% and 20% in the general older adults [
56] and 5% and 17% in primary care conditions [
57]. The prevalence of depressive symptoms is reportedly higher than that of depression [
58]. In Poland, few studies have been conducted to assess the incidence of depression in the elderly. In the WOBASZ study, the symptoms of depression were found in more than 25% of the examined population [
59]. The PolSenior study reported that the morbidity of depressive disorders increased with age (20% in the 55–59 age group, 25% in the 65–79 age group, 33% in those 80 and over) [
1].
In our study, the overall BDI result showed that the feeling of the severity of depressive symptoms may have indicated mild depressive disorders. In the study by Goldberg et al. [
60] depressive symptoms were highly prevalent and they indicated major depressive disorders. In our study, sex was not significantly related to BDI point values. However, from the statistical point of view, group affiliation and age significantly affected the BDI results. Similarly to our study, the results in the study by Segal et al. [
61] suggested no statistically significant relationship between the influence of age and sex on the BDI results.
Right after dementia, depression is the main factor causing increased health care costs for older adults. It is predicted that by 2020 it will be the main cause of morbidity among seniors [
62,
63].
Limitations of the study
The main limitation of the study was the small size of the study groups. In addition, the study was conducted only in one city (Bialystok), which may not reflect the results for the whole country. The study involved only residents of Bialystok, as the authors are employees of the Medical University of Bialystok; therefore, it was easier to access the inhabitants of this city. Another limitation was the selection of a test group. There was a risk that the retirement university communities may have been less suitable for comparison with nursing home residents. They were probably not the best choice for true representation of the whole population of the region, as they were likely to have better physical health and be more prosperous than other members of the community. Moreover, they may have been more affluent than inhabitants of nursing homes. In the analysis, only the raw prevalent data were presented without adjustments for physical limitations, chronic diseases, etc. Differences in mental distress amongst older adults and those in nursing homes were likely due to the presence of other factors, e.g. pain affecting the participants’ mental state, rather than due to being old or living in a nursing home.