Epidemiological characteristics of subsyndromal depression in late life

Abstract

Objectives: Subsyndromal depression is prevalent and associated with poor outcomes in late life, but its epidemiological characteristics have barely been investigated. The aim of this prospective cohort study is to compare the prevalence, incidence and risk factors of subsyndromal depression with those of syndromal depression including major and minor depressive disorders in community-dwelling elderly individuals. Methods: In a nationwide community-based study of randomly sampled Korean elderly population aged 60 years or older ( N = 6640), depression was assessed with standardized diagnostic interviews. At baseline and at 2-year and 4-year follow-ups, the authors diagnosed subsyndromal depression by the operational criteria and syndromal depression by the Diagnostic and Statistical Manual of Mental Disorders (4th ed.) diagnostic criteria. Multivariate logistic regression analyses were conducted to identify the risk factors for incident depression. Results: The age- and gender-adjusted prevalence rate of subsyndromal depression was 9.24% (95% confidence interval = [8.54, 9.93]), which was 2.4-fold higher than that of syndromal depression. The incidence rate of subsyndromal depression was 21.70 per 1000 person-years (95% confidence interval = [19.29, 24.12]), which was fivefold higher than that of syndromal depression. The prevalence to incidence ratio of subsyndromal depression was about half that of syndromal depression. The risk for subsyndromal depression was associated with female gender, low socioeconomic status, poor social support and poor sleep quality, while that of syndromal depression was associated with old age and less exercise. Conclusion: Subsyndromal depression should be validated as a clinical diagnostic entity, at least in late life, since it has epidemiological characteristics different from those of syndromal depression.

Chronic subsyndromal depression and risk of dementia in older adults

“…These results suggest that chronic/recurrent SSD with increasing severity may be a high-risk condition for dementia distinct from MCI, and our results are consistent with those of previous studies that reported that mild behavioral impairment, especially affective dysregulation, increases the risk of dementia in the psychiatric outpatient population (Ismail et al, 2016;Liew, 2020). Late in life, SSD is about 2.5 times more prevalent and has about five times greater incidence compared with clinically significant syndromal depression, such as MDD and mDD (Oh et al, 2019). More than half of the cases of SSD are chronic in both community (59-74%) (Beekman et al, 2002;Cohen et al, 2009) and primary care (51-70%) (Cui et al, 2008;Lyness et al, 2002Lyness et al, , 2009 settings.…”

“…Third, the information about the degree of antidepressant exposure was limited, although several studies have identified the association between anticholinergic antidepressants and dementia risk (Coupland et al, 2019;Richardson et al, 2018). Finally, although the epidemiological and biological characteristics of SSD defined by our operational diagnostic criteria were well documented (Jeong et al, 2012;Oh et al, 2019;Park et al, 2015), the criteria need consensus from experts.…”

“…At the baseline and each follow-up evaluation, geriatric psychiatrists administered face-to-face standardized diagnostic interviews for the diagnosis of depressive disorders using the Korean version of the Mini International Neuropsychiatric Interview (MINI-K) (Sheehan et al, 1998;Yoo et al, 2006). They diagnosed syndromal depression such as major and minor depressive disorders using the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) criteria and SSD using the operational criteria (Oh et al, 2019). The operational diagnostic criteria for SSD were as follows: (a) the occurrence of two or more symptoms of depression listed in criterion A for major depressive episode in the DSM-IV within the same 2-week period; (b) the presence of at least a depressed mood or anhedonia; (c) each depressive symptom should be present for more than half a day or more than 7 days during the 2-week period; (d) participants must not fulfill the criteria for the diagnosis of major depressive disorder (MDD) or minor depressive disorder (mDD); (e) the symptoms must not be due to the direct physiological effects of a substance or a general medical condition; (f) the symptoms must not be attributable to bereavement, dementia or schizophrenia and other psychotic disorders; and (g) there should not be a history of the occurrence of a manic or hypomanic episode.…”

“…However, very few studies have investigated whether subsyndromal depression (SSD) increases the risk of dementia. SSD is more prevalent than clinically significant depression, such as major or minor depressive disorders in late life (Meeks et al, 2011;Oh et al, 2019), and is associated with as many adverse outcomes (e.g. poor physical health, disability, health care utilization and mortality) as clinically significant depression (Beekman et al, 1997;Hybels et al, 2009;Meeks et al, 2011;Penninx et al, 1999).…”

The impact of the COVID-19 pandemic on depression in community-dwelling older adults: a prospective cohort study

“…The diagnostic interview using the MINI-K was administered after the evaluations by trained research nurses and neuropsychological researchers with an interval of 1 week. We made a diagnosis of depressive disorder when a participant exhibited major or minor depressive disorders according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) criteria or subsyndromal depression according to the operational diagnostic criteria (Oh et al, 2020 ). The participants without any current depressive disorder and manic/hypomanic episode were defined as euthymic participants.…”