Apathy in early and late-life depression

Highlights

• Apathy, as clinical syndrome, was significantly more often present in older compared to younger depressed persons.

• In both older and younger depressed persons higher severity of depression was associated with more apathy.

• Smoking was associated with the presence of apathy in older but not in younger depressed persons.

• Age, male gender and severeness of depression were independently associated with presence of apathy in depressed persons.

Abstract

Background

Late-life depression is thought to differ in clinical presentation from early-life depression. Particularly, late-life depression is considered to be more characterized by apathy than is early-life depression. Lacking convincing evidence, this study examines the presence and associated socio-demographic/clinical characteristics of apathy in older compared to younger depressed persons.

Methods

This cross-sectional study used data from two naturalistic cohort studies, i.e. the Netherlands Study of Depression in Older Persons (NESDO) and the Netherlands Study of Depression and Anxiety (NESDA). These studies included 605 persons (aged 18–93 years) with a major depressive disorder, divided into 217 early-life (< 60 years) and 388 late-life (≥ 60 years) depressed persons. Apathy was considered present if a score of ≥14 on the Apathy Scale.

Results

Apathy was strongly associated with age: it was more frequently present in persons with late-life depression (74.5%) than in those with early-life depression (53.5%). Independent of age, the following characteristics were associated with the presence of apathy: male gender, low education, use of benzodiazepines, chronic diseases, and more severe depression. Of all potential risk factors, only former and current smoking was associated with the presence of apathy in older depressed persons but not in younger depressed persons (p-value for age interaction = 0.01).

Limitations

No causal relationships can be drawn due to the cross-sectional design of the study.

Conclusions

In depressed individuals, clinically relevant apathy was more frequently present in older compared to younger persons. Both age groups showed largely the same associated risk factors. Apathy was independently associated with older age, male gender and more severe depression.

Introduction

Depression is one of the most prevalent psychiatric disorders, affecting 5–8% of the population worldwide (Shahpesandy, 2005). It is often stated that depressive symptoms differ between younger and older depressed persons. For example, studies have demonstrated that late-life compared to early-life depressed persons show increased psychomotor retardation, decreased activity (Brodaty et al., 1997, Brodaty et al., 1991, Shahpesandy, 2005) and show less mood symptoms (i.e. feelings of guilt) (Hegeman et al., 2012, Lyness et al., 1995, Shahpesandy, 2005, Yates et al., 2004), all of which resemble symptoms of apathy. Therefore, apathy may be considered to be a characteristic feature of especially late-life depression (Shahpesandy, 2005). However, apathy (as a clinically relevant syndrome) can be diagnosed when a cluster of clinical features is present (consisting of a loss of motivation, interest and concern) resulting in decreased goal-directed behavior, emotional responsivity and cognitive activity.

Distinguishing apathy (as a syndrome) from depression can be a major challenge due to an overlap in symptoms, e.g. loss of interest, which is also found in anhedonia. Although both apathy and anhedonia indicate lack/decrease of interest, the latter presents a state of decreased experienced pleasure in activities, whilst apathy is characterized by a lack of primary motivation and affective dullness (Kaji and Hirata, 2011, Kirsch-Darrow et al., 2011).

Studies in different populations show that the following risk factors are associated with apathy as a clinically relevant syndrome in old age: vascular disease, excessive use of alcohol, use of benzodiazepines, smoking and the presence of chronic diseases (Adams, 2001, Clarke et al., 2010, Lyvers et al., 2013, Lyvers et al., 2014, Maas et al., 2009, Moselhy et al., 2001, Onyike et al., 2007, Semprini et al., 2012, van der Mast et al., 2008, van Duijn et al., 2010, Winhusen et al., 2013). The few studies on clinically relevant apathy in depressed persons have focused mainly on older populations. In one cross-sectional study in depressed older persons: i) clinically relevant apathy was associated with severity of depression; whereas, longitudinally: ii) impaired cognitive function at baseline predicted incident apathy, and iii) more severe apathy at baseline predicted persistence of apathy and depression, whereas iv) remitted apathy was associated with less use of benzodiazepines (Groeneweg-Koolhoven et al., 2016). In addition, no association was found between apathy and the use of antidepressants or presence of cardiovascular diseases (Groeneweg-Koolhoven et al., 2016). Further, apathy appeared to be a predictor of poor response to antidepressant treatment (Levkovitz et al., 2011, Wongpakaran et al., 2007), chronicity of depression (Groeneweg-Koolhoven et al., 2016, Lavretsky et al., 1999), a poor prognosis, and increased overall mortality rates (Lavretsky et al., 2010, Yasuda et al., 2002). Improved treatment of clinically relevant apathy within a depressed group would ameliorate the prognosis. Therefore, it is of clinical relevance to have better understanding of the position of clinically relevant apathy in depressed persons (Brodaty et al., 1997, Brodaty et al., 1991, Shahpesandy, 2005).

Systematic studies measuring the same apathy concept in late-life and early-life depression are lacking. Consequently, it is unknown whether apathy as a distinct and clinically relevant syndrome is indeed much less present in depressed younger persons than in depressed older persons; and, if so, whether apathy has similar associating sociodemographic and clinical correlates in older depressed persons compared to younger depressed persons.

Therefore, the present study examines whether: the prevalence of apathy (as a distinct clinically relevant syndrome) differs between late-life and early-life depression and whether certain late-life comorbidities (e.g. chronic diseases, atherosclerosis, severity of depression, use of alcohol, use of benzodiazepines and smoking) partly explain such an age difference. In addition, we examined whether the found determinants of apathy are more important (moderating) in late-life than in early-life.