Urinary incontinence (UI), which is defined as the involuntary leakage of urine [1] is highly prevalent in the general population and can severely affect many aspects of daily life [2, 3]. Although this condition can exist in adults of all ages [3], a large body of research has shown that the prevalence of UI increases with age [4, 5] and that the elderly are especially vulnerable to this condition [6] particularly in a severe form [7, 8]. While previously reported prevalence figures vary due to the different operational definitions of UI employed (type, severity etc.), an earlier review article presented figures which showed that the prevalence of UI ranges between 9 and 59% in those aged 50 and above [9].

Studies have indicated that UI can have a significant negative effect on the lives of older people [10]. For example, it has been associated with troublesome symptoms such as aches, pain, weakness, and shortness of breath [11], as well as with an increased risk for outcomes such as falls and fractures [12, 13]. The avoidance of physical activity in an attempt to manage/control the condition may also have an effect on overall health by increasing the risk of conditions such as hypertension [14, 15]. In addition, UI is also associated with poorer mental health among older persons including anxiety disorders [16] and depression [16, 17].

Despite the large number of studies on UI and its associated adverse health outcomes, one condition which has been little studied to date in relation to UI is loneliness. This is an important research gap given that: (a) incontinent individuals can experience feelings of frustration, embarrassment and shame [18, 19] as a result of their condition and will sometimes reduce/avoid social contacts and activities in order to control UI and its effects [18], which may lead to increased social isolation and feelings of loneliness; and (b) loneliness has itself been linked to an increased risk for morbidity and mortality among older persons [20, 21]. To the best of our knowledge, to date, there have been only three studies which have investigated this association. Specifically, two recent studies have shown that older adults (≥57 years old) with UI in Canada and the United States have an increased risk of feeling lonely compared to those who are continent [22] or who have no/less severe UI symptoms (no/weekly/monthly/yearly vs. daily) [23], respectively. An earlier study from the United States also found similar results where UI and UI severity (measured by the quantity of urine loss) were both associated with loneliness among middle-aged and older adults (≥ 40 years old) [24].

Although these studies have advanced understanding of the psychological consequences of UI, there are aspects of the association between UI and loneliness among older adults that are yet to be elucidated. In particular, there has been an absence of research on the role of common mental disorders (CMDs) in this association. This is an important gap in the research as not only are anxiety and depression linked to UI in older persons [16, 17], but other research has highlighted their close link with loneliness in older adults [25–27] and that in middle-aged and older adults, depressive symptoms and loneliness may be reciprocally related [28]. Therefore, there is a need to assess the extent to which CMDs explain the association between UI and loneliness. In addition, until now, there has been no research on whether the specific consequences of UI, such as activity limitations, are important for loneliness in older adults.

Thus, using data from a nationally representative sample of community-dwelling older adults (aged 50 and above) in Ireland, the current study had three aims: (1) to determine if UI is associated with an increased risk of feeling lonely; (2) to examine if the severity of UI, as measured by the frequency of urine loss and activity limitations, is associated with loneliness; and (3) to assess the role of CMDs in the association between UI, UI severity and loneliness.

Using data from a nationally representative sample of community-dwelling older Irish adults, this study showed that having any UI was associated with an increased risk for loneliness. When depression or anxiety was included in the analysis ORs were attenuated, particularly for depression, which suggests that this association is mainly explained by depression. Worse mental health was also important in the relation between UI severity and loneliness as depression fully attenuated the significant association between an increased frequency of UI and loneliness, while an association between activity limitations and loneliness became non-significant when both depression and anxiety were included in the fully adjusted model. When the analysis was restricted to those with UI, depression alone fully attenuated the significant association that was observed between activity limitations and loneliness.

The finding that UI was associated with loneliness when not adjusting for mental health conditions, accords with the results of earlier studies in Canada and the United States [22–24]. This result seems plausible given that UI has been linked to a range of ‘safety-seeking behaviors’ that are used to manage the condition and its effects, such as avoiding contact with others, intimacy and activities outside the home [45] that might all lead to social isolation among those with UI and give rise to feelings of loneliness. Moreover, the results from the analyses examining UI severity also seem to support this idea as activity limitations were strongly associated with loneliness in the whole sample and when the analysis was restricted to those with UI. Being treated differently by other people because of their condition [18] might also act to isolate those with UI and lead to feelings of loneliness, especially as a recent study from the United States has indicated that older women with daily UI often feel left out and that they lack companionship [23].

When the common mental disorder variables, in particular, depression, were entered into the analysis, however, the association between UI, UI severity and loneliness became non-significant. Together with our finding that those with UI are more likely to experience greater anxiety and depression, this suggests that poorer mental health might be an intervening variable between UI and loneliness. It can only be speculated what underlies the association between depression and loneliness among those with UI, as even though earlier research has indicated that they can both influence each other over time [28], as yet, there has been comparatively little research on the specific mechanisms linking depression to loneliness [27]. It is possible, for example, that certain psychological resources might be important in this context. Specifically, a recent study has reported that a lower sense of mastery significantly contributes to the association between depression and (emotional) loneliness [27] while other research has indicated that UI is associated with a lower sense of mastery [46] and that there is an association between a poor sense of mastery and depression in those with UI [47]. One of the safety-seeking behaviors among those with UI – inquiring frequently if he or she smells [45] – might also be a factor that links depression and loneliness, as a more general connection has been shown to exist between seeking reassurance excessively and both depression and interpersonal rejection [48].

There are several limitations that should be borne in mind when considering this study’s findings. UI data were self-reported in this study. Given the stigma and embarrassment that is associated with UI, it is possible that underreporting may have been an issue [4], although the prevalence estimate obtained fell within the range of those reported in other studies. We also lacked information on the type of UI that was experienced. This might be an important omission as there is some evidence that urge incontinence may affect well-being more than stress incontinence [11] and have a stronger association with worse mental health [49]. There may have also been a problem with one of the instruments used in this study. Specifically, a recent systematic review has questioned the ability of HADS to clearly differentiate between anxiety and depression and indicated that it might be better regarded as a measure of ‘emotional distress’ [50]. In addition, since individuals with cognitive impairment that was severe enough to preclude participation in the survey, and the institutionalized were not included in our study sample, the study results cannot be generalized to this population. Finally, as this study was cross-sectional, it was not possible to determine causality or the temporality of the observed associations.

This study, which used data from a nationally representative sample of almost 7000 community dwelling adults aged ≥ 50, has shown that UI and UI severity are linked to loneliness but that this association is largely dependent on the presence of comorbid depression. The results of this study and the detrimental (psychological/mental health) outcomes that have been reported in earlier studies, together with the fact that at least one-third of older adults with UI do not seek help [14], suggest that more effort is required to educate older respondents about this condition and its effects, as well as about the wide variety of treatment options that are available for it [51]. For patients, clinician screening for loneliness and then referral to agencies that run social programs (e.g. group meals) that might help alleviate this phenomenon [52] may be one way to improve the quality of life in those individuals with UI. In addition, as poorer mental health is more prevalent among people with UI, and can affect the course and outcome of UI [49, 53], routine mental health screening and close collaboration with mental health professionals may also prove efficacious for patients with UI.