Personality and late-life depression (WC2013-088)

Personality and late-life depression

Background

Starting date: 01/12/2013

 

There is increasing interest in the contribution of personality characteristics in late-life depression. A new trend is going on, also reflected by the recent version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5, American Psychiatric Association, 2013), to approach personality in a dimensional way instead of merely in terms of disorders. In our study, we will adopt this approach by studying personality according the Five Factor Model (FFM, McCrae and Costa, 2008), which consists of five domains: Neuroticism (easily upset, not calm, maladjusted), Extraversion (energetic, assertive, talkative), Conscientiousness (responsible, dependable, orderly), Openness to Experience (imaginative, independent-minded, intellectual), and Agreeableness (good-natured, cooperative, trusting). Current evidence suggests that especially Neuroticism is strongly related to the occurrence (Duberstein et al., 2008; Hayward et al., 2013; Steunenberg et al., 2006; Weber et al., 2011), course (Duberstein et al., 2008; Canuto et al. 2009; Kling et al., 2003; Steunenberg et al., 2007, Steunenberg et al., 2009; Weiss et al., 2009)  and treatment outcome (Canuto et al., 2009; Hayward et al., 2013; Weber et al., 2011) of  late-life depression. Other Big Five domains are far less studied regarding late-life depression, but there is modest evidence for an association between lower levels of Extraversion (Weber et al., 2010; Weber et al., 2011 ), Conscientiousness (Hayward et al., 2013; Weber et al., 2012) and Openness (Weber et al., 2012) and  late-life depression diagnosis.

Compared to the younger adult population (age 18-60 years), the role of Big Five personality factors and depression in older adults (age >60 years) has only been studied on a limited scale and it therefore deserves a more thorough consideration. In a recent study (Koorevaar et al., 2013) we examined the association between Big Five personality factors and several depression characteristics, including diagnosis, severity and age of onset. Both the presence of a depression diagnosis and severity of depression were significantly associated with higher Neuroticism (OR=1.35, 95% CI=1.28−1.43 and B=1.06, p<.001, respectively) and lower Extraversion (OR=.79, 95% CI=.75−.83; B=−.85, p<.001) and Conscientiousness (OR=.86, 95% CI=.81.−.90; B=−.86, p<.001). Earlier onset of depression was significantly associated with higher Openness (B=−.49, p=.026). 

Although the outcomes of our study confirms an association between late-life depression characteristics and Big Five personality, important issues remain unclear and deserve a more thorough consideration.

First, we did not make a distinction between subtypes of depression, such as episodic versus chronic forms of depression, or melancholic versus atypical depression. Recent studies in younger adults suggest chronic depressed patients having more unfavourable personality characteristics, compared to patients with an episodic depression (Kotov et al., 2010; Rhebergen et al., submitted; Wiersma et al., 2011). It has often been stated that chronic depression in older adults should be less associated with adverse personality characteristics (Bellino et al., 2000; Devanand et al., 1994; Devenand et al., 2000; Kirby et al., 1999; Kocsis, 1998), although outcomes of a recent study question this point of view (Mackenzie et al., 2013). Further, recent outcomes of studies in the younger adult population showed personality associated with severity and duration as classifying dimensions of depression, while its association with atypical or melancholical depression is less evident (Lamers et al., 2010; Lamers et al., 2012). Because studies in the elderly population on subtypes or classifying dimensions and personality are hardly available, we want to be the first to study this topic in a comprehensive way. Further, we will study this from both a top down, DSM driven approach as well as a bottom up, data-driven approach.

Second, we want to study the role of personality in the course of late-life depression. As previously mentioned, Neuroticism has often been associated with the maintenance of late-life depression (Steunenberg et al., 2009). However, additional evidence is needed concerning the other Big Five domains and their possible role in the course of late-life depression.

In addition, we will investigate the stability of personality measure in the course of depression. Several studies have demonstrated that the Big Five personality factors are relatively stable over time, even during a depressive episode (Costa et al., 2005; McCrae & Costa, 2008; Morey et al., 2010; Steunenberg et al., 2005), or that they are at most only modestly influenced by mood disorders (Costa &Mc Crae, 2005; Karsten et al., 2012). However, others have argued that personality, and Neuroticism in particular, is just a reflection of a perceived psychological distress (Ormel et al., 2004), making clear that it is still an actual topic of debate.

Third, we want to study the role of other clinical characteristics in the association between personality and late-life depression. For example, in our recently published study we found that childhood trauma and functional limitations played a confounding role in the association between personality and the severity and age of onset of late-life depression (Koorevaar et al., 2013). This finding rises questions about the nature and mutual influence of these associations, and asks for a more thorough investigation.

Finally, we want to take a meta-perspective on the role of personality and late-life depression by investigating the relative impact of personality in the course of late-life depression, compared to other psychological, social, physical and cognitive factors which are known to be related to late-life depression as well.  Futher, we want to clarify whether the role of personality differs between youngerly and elderly depressed, by comparing the unique contribution of personality in the presence and course of depression in older patients with younger patients.  As far as we know, we will be the first to conduct such a comprehensive study on personality in depressed elderly and adult patients.