Fanous AH, Neale MC, Aggen SH, Kendler KS. A longitudinal study of personality and major depression in a population-based sample of male twins. Psychol Med 37: 1163-1172

Virginia Commonwealth University, Ричмонд, Virginia, United States
Psychological Medicine (Impact Factor: 5.94). 09/2007; 37(8):1163-72. DOI: 10.1017/S0033291707000244
Source: PubMed


The relationship between personality and psychiatric illness is complex. It is not clear whether one directly causes the other.
In a population-based sample of male twins (n=3030), we attempted to predict major depression (MD) from neuroticism (N) and extraversion (E) and vice versa, to evaluate the causal, scar, state, and prodromal hypotheses. In a longitudinal, structural equation twin model, we decomposed the covariation between N and MD into (a) genetic and environmental factors that are common to both traits, as well as specific to each one and (b) direct causal effects of N at time 1 on subsequent MD, as well as between MD and subsequent N.
E was negatively correlated with lifetime and one-year prevalence of MD. N predicted the new onset of MD, and was predicted by both current and past MD. It did not predict the time to onset of MD. All of the covariation between N and MD was due to additive genetic and individual-specific environmental factors shared by both traits and a direct causal path between MD and N assessed later. No genetic factors were unique to either trait.
In men, N may be a vulnerability factor for MD but does not cause it directly. However, MD may have a direct causal effect on N. The genetic overlap between N and MD in men may be greater than in women.

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    • "Adjusting for neuroticism at Time 1, those with new occurrence of MDD in the intervening period had higher neuroticism at Time 2, especially those with current MDD at Time 2. After controlling for their common genetic and environmental influences, the bestfitting twin model indicated that MDD had a small causal influence on neuroticism, consistent with a stagnation process. These findings were then replicated in a large sample of male twins (Fanous et al., 2007). Notably, these two studies were longitudinal but not developmentally informed as the samples included adults of a wide age range, varying in proximity to periods of greatest change in NE traits. "
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    ABSTRACT: A dominant paradigm in psychopathology research proposes that individual differences in personality are centrally involved in the origins and manifestations of psychopathology, and structural models of personality and psychopathology have been extremely useful in helping to organize associations among many traits and disorders. However, these models merely describe patterns of covariation; they do not explain the processes by which these patterns emerge. We argue that the field is stagnated, as it is overly focused on the demonstration of concurrent associations and on confirming a spectrum model that proposes traits and disorders are manifestations of the same underlying constructs. We contend that if the field is to move towards an understanding of causal processes, it must integrate knowledge and principles of personality development and developmental psychopathology. To begin this integration, we review (i) normative trends in personality change, (ii) age-related changes in the prevalence of disorders, and (iii) the impact of onset and chronicity on the severity of disorders. We propose several developmental processes that may contribute to the co-development of personality and psychopathology. We then present novel empirical findings to illustrate how a developmental perspective on traits and disorders can inform new hypotheses and propose principles and hypotheses that should guide future research. Copyright © 2014 European Association of Personality Psychology
    Full-text · Article · Jul 2014 · European Journal of Personality
    • "These studies have shown that MDD is positively associated with neuroticism and negatively with extraversion. Moreover, clinical and population based studies have identified neuroticism as an important vulnerability factor for MDD (Boyce et al., 1991; Fanous et al., 2007; Hettema et al., 2006; Hirschfeld et al., 1989; Kendler et al., 2006; Kendler et al., 2004; Ormel et al., 2004), whereas low extraversion appears to be associated only weakly to MDD (Kendler et al., 2006). "
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    ABSTRACT: BACKGROUND: The personality dimensions neuroticism and extraversion likely represent part of the vulnerability to depression. The stability over longer time periods of these personality dimensions in depressed patients treated with psychological treatment or medication and in untreated persons with depression in the general population remains unclear. Stability of neuroticism and extraversion in treated and untreated depressed persons would suggest that part of the vulnerability to depression remains stable over time. The current study addressed the question whether treatment in depressed patients is related to changes in neuroticism and extraversion. METHODS: Data are from 709 patients with major depressive disorder participating in a cohort study (Netherlands Study of Depression and Anxiety; NESDA). We determined the 2-year stability of extraversion and neuroticism in treated and untreated persons and related change in depression severity to change in personality over time. RESULTS: Neuroticism decreased from baseline to 2-year follow-up (d=0.73) in both treated and untreated persons. Extraversion did not change significantly after controlling for neuroticism and depression severity at baseline and follow-up. Decreased depressive symptoms over time were related to decreased neuroticism (d=1.91) whereas increased depressive symptoms over time were unrelated to neuroticism (d=0.06). LIMITATIONS: Patients were not randomized to treatment conditions and the groups are therefore not directly comparable. CONCLUSIONS: Treated patients with depression in the general population improve just as much on depression severity and neuroticism as untreated persons with depression. This suggests that changes in neuroticism in the context of treatment likely represent mood-state effects rather than direct effects of treatment.
    No preview · Article · Apr 2013 · Journal of Affective Disorders
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    • "The results that we observe probably reflect several mechanisms. Most important is probably the fact that neuroticism reflects an underlying liability to MDD (Boyce et al., 1991; Fanous et al., 2007; Kendler et al., 1993; Nystrom and Lindegrard, 1975). At least two other mechanisms likely play a role: a direct effect of MDD on the level of neuroticism for those currently in an episode (“state” effect) (Coppen and Metcalfe, 1965; Fanous et al., 2007; Farmer et al., 2002; Hirschfeld et al., 1983; Kendler et al., 1993; Kerr et al., 1970) and a long-term effect of prior depressive episodes on neuroticism (“scar” effect) (Fanous et al., 2007; Farmer et al., 2002; Kendler et al., 1993; Reich et al., 1987). "
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    ABSTRACT: The personality trait of neuroticism is a risk factor for major depressive disorder (MDD), but this relationship has not been demonstrated in clinical samples from Asia. We examined a large-scale clinical study of Chinese Han women with recurrent major depression and community-acquired controls. Elevated levels of neuroticism increased the risk for lifetime MDD (with an odds ratio of 1.37 per SD), contributed to the comorbidity of MDD with anxiety disorders, and predicted the onset and severity of MDD. Our findings largely replicate those obtained in clinical populations in Europe and US but differ in two ways: we did not find a relationship between melancholia and neuroticism; we found lower mean scores for neuroticism (3.6 in our community control sample). Our findings do not apply to MDD in community-acquired samples and may be limited to Han Chinese women. It is not possible to determine whether the association between neuroticism and MDD reflects a causal relationship. Neuroticism acts as a risk factor for MDD in Chinese women, as it does in the West and may particularly predispose to comorbidity with anxiety disorders. Cultural factors may have an important effect on its measurement.
    Full-text · Article · Aug 2011 · Journal of Affective Disorders
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