The Effect of Childhood Trauma on Personality in Unaffected First-Degree Relatives of Major Depressive Disorder


 Objectives: This study is aimed to examine the potential association between childhood trauma (CT) and personality traits among unaffected first-degree relatives (FDR, children or siblings of patients) of patients with major depressive disorder (MDD). Methods: The study consists of three groups: total 85 patients with MDD, 35 FDRs and 89 healthy control individuals (HC). The Childhood Trauma Questionnaire (CTQ) was used to assess childhood trauma and the Eysenck Personality Questionnaire used to assess personality traits. Results: By comparison made in personality traits, MDD patients exhibits some significant disparities to FDR and HC (p<0.05 for extraversion, neuroticism and psychoticism). Nevertheless, no significant difference was found between HC and FDR. In FDR group, patients with CT scored noticeably higher for neuroticism (N) compared with those without CT (F=3.246, p=0.046). CT was associated with N, psychoticism (P) and Lie (L), and it was associated with N more closely (r=0.290-0.452, p<0.05 for all). Significantly positive correlations were found between N and sexual abuse (SA), emotional neglect (EN), physical neglect (PN), and CTQ total (r=0.344-0.452, p<0.05); P and CTQ (r=0.336, p<0.05); and significant negative correlations between L and EN, CTQ (r=-0.446-0.375, p<0.05). EN contributed to a probability of N, P (R2=0.155-0.214, F=6.066-9.010, p=0.005-0.019) as well as a probability of L (R2=0.199, F=8.211, p=0.007). Conclusion: CT was associated with N, P and L, with a closer relation to N in unaffected FDR. Besides, the type of CT, the most relevant to N, was discovered to be EN. Thus, FDR of MDD who experienced CT should be prioritized. Key words: childhood trauma; personality; major depressive disorder; first-degree relatives

generated or analyzed during this study are included in this article. 23 Competing interests: there are no ethical/legal conflicts involved in the article.  Numerous studies have supported the correlation between personality and the 115 presence of major depressive disorder (MDD) [1,2]. Compared with non-affected 116 controls, patients with MDD often have higher scores on neuroticism [3], and the score 117 tend to decrease when patients show improvement of achieve remission [4]. Besides, a 118 higher score on neuroticism has been found to be predictive of poorer outcome in 119 patients with MDD [5-7]. Population-based twin studies showed that the association 120 between neuroticism and MDD may be in part due to shared genetic factors, and they 121 found the genetic correlation with neuroticism was 0.46-0.47 based on their study of 122 20,692 same-sex twin pairs in Sweden [8]. Personality traits appear to be vital for the 123 onset and course of depression in many ways [9,10] These studies all suggest that there is a complex association between CT,  The inclusion criteria for the study were as follows: (1) aged between 16 and 55;

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(2) received more than 9 years of formal education; (3) was able to understand and 163 willing to sign an informed consent. Participants with any of the following were  175 The CTQ-SF is a 28-item self-report retrospective inventory intended to measure scales. Severity of each trauma category based on cut-off scores was quantified as "none 9 participants as positive for history of specific trauma category. The CTQ cut-off scores 187 for "moderate (to severe)" are as follows: EA≥13, PA≥10, SA≥8, EN≥15, and PN≥10. 188 189 The EPQ is a self-report questionnaire for measuring personality dimensions

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There were no significant differences in sex, age and education level between the 222 three groups (Table 1). There was a significant difference in age (P=0.02) between those 223 with and without CT in FDRs (based on the cut-off), but no significant differences in 224 other aspects (Table 2).

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There were no significant differences in personality traits between FDRs and HC.  Details please see Table 1.

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Factors that failed to match up were included as co-variates in subsequent 233 comparisons. People with CT had significantly higher N scores than those without CT 234 in FDRs (F=3.246, p=0.046). The same was found in HC (t=-2.387, p<0.05);

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Significantly negative correlations were found between L and EN, CTQ (r=-0.446 --241 0.375, p<0.05) ( Table 3).  (Table 4). This study was the first to verify the association between CT and personality traits 265 in unaffected FDRs of patients with MDD. We found no significant differences between 266 FDR and HC in personality traits. In FDRs, CT was associated with a higher score on 267 neuroticism, psychoticism and lie, with the association with neuroticism the strongest.

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Besides, in terms of subtype, emotional neglect was the one to be found to have the 269 strongest association with neuroticism.  [15], our study showed personality traits were significantly associated with childhood subtype of childhood trauma that were most associated with neuroticism was emotional 307 neglect. Difference from our findings, a few other studies reported emotional abuse was 308 the one with the strongest association with neuroticism in healthy controls (references 309 here); and individual with avoidant personality disorder [42,43]. It is worth noting, 310 they also found that emotional neglect was associated with neuroticism, secondary to