Edited by: Gábor Gazdag, Jahn Ferenc Dél-Pesti Kórház és Rendelointézet, Hungary
Reviewed by: Vedat Sar, Koç University, Turkey; Seon-Cheol Park, Hanyang University Guri Hospital, South Korea; Christopher Hübel, King's College London, United Kingdom; Jessica Mundy, King's College London, United Kingdom, in collaboration with reviewer CH
This article was submitted to Mood Disorders, a section of the journal Frontiers in Psychiatry
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There is an association between early life traumas and the development of depression in adults. Few studies have used nationwide population-based samples to investigate whether the type of early life trauma differentially influences the risk of developing depression.
Major depressive disorder and early life trauma were assessed using the Korean version of the Composite International Diagnostic Interview (K-CIDI) for DSM-IV psychiatric disorder and a questionnaire for early life trauma in the Korean Epidemiological Catchment Area Study in 2016. A total of 4,652 participants were included in the final analysis. This study evaluated the effect of the type and frequency of reported early life trauma on the risk of developing MDD and the association between reported early life trauma and differential symptoms of MDD.
Individuals with reported early life trauma had a 3.7-fold increased risk of MDD. The risk of MDD was associated with bullying trauma (odds ratio (OR) = 1.847,
Bullying trauma during early life represents a risk factor for MDD, especially in individuals exposed to multiple traumas in early life.
Exposure to trauma in early life is associated with various psychopathologies and poor outcomes in adulthood (
Major depressive disorder (MDD) is one of the most prevalent psychiatric disorders, with a lifetime prevalence between 8% and 12% (
Previous studies showed that early life trauma increases the risk of depression. However, it is inappropriate to regard early life trauma as a single phenomenon, so each type needs to be considered separately (
Thus, we attempted to characterize the relationship between different types of early life trauma and MDD using a nationwide community sample of South Koreans. The primary aim of the study was to identify the influence of the type and frequency of early life trauma on the presence of MDD. The secondary aim of the study was to explore the associations between early life trauma and the different symptoms of MDD.
Data were collected by the 2016 Korean Epidemiological Catchment Area Study (KECA-2016) from April to November of 2016. The purpose of this study was to determine the lifetime and 12-month prevalence of mental disorders, socioeconomic correlates, and comorbidities every 5 years among Korean adults. The subjects of this study were ordinary adults over the age of 18 who live in the community. This study was intended to determine the prevalence of the general population and did not include people in hospitals or nursing homes. The respondents were evenly selected from 21 community catchment areas throughout the country by a stratified multistage cluster sampling method to generate national representative data. Since the population of each survey area was different, the number of subjects in each survey area was estimated by considering the ratio of the population of each survey area to the total population of Korea. Using the last-birthday method, the individual with the earliest birthday was randomly selected and interviewed. The institutional review board of Seoul National University College of Medicine approved all study procedures. All subjects were fully explained about the purpose and method of the study, and informed consent was obtained prior to participation. A total of 5,102 subjects aged over 18 years participated in face-to-face interviews.
The 147 interviewers with academic backgrounds in medicine, nursing, and social welfare living in the survey area were recruited from each catchment. The training of the interviewers was conducted by professional instructors in a central training center accredited by the WHO. The training was conducted for five full-time days by an instructor with qualifications of a psychiatrist or higher in accordance with the WHO recommendation standards. In addition to training for each CIDI session, mock interviews were conducted, and at the end, live interview with real patients were conducted. Live interviews with psychiatric patients followed by group discussions were conducted to confirm inter-rater reliability. For the qualitative management of the investigation, in addition to the interviewers, a field manager was assigned to supervise the interviewers, check the results of the investigation, and supervise the progress of the investigation.
The Korean version of the Composite International Diagnostic Interview (K-CIDI) version 2.1 was used for assessing participant mental health (
The self-report questionnaire assessing early life trauma consisted of five items including bullying, emotional neglect, and psychological, physical, and sexual trauma. Bullying was evaluated using an item in the adverse childhood experiences international questionnaire (ACE-IQ) (
Emotional neglect, psychological trauma, physical trauma and sexual trauma was assessed using a questionnaire based on the NEMESIS-1 trauma questionnaire (
The experience of bullying trauma was measured by asking “How many times have you been bullied as you grew up, at or before the age of 18?” The experience of emotional neglect, psychological, physical, and sexual trauma was measured by asking “Growing up, do you think there was any kind of emotional neglect or psychological, physical, and sexual trauma at or before the age of 18?” The trauma questionnaire responses were coded on a 4-point scale (1: none, 2: once, 3: a few times, 4: many times). Based on the number of coding results, for each specific early life trauma, 1(none) was defined as those who did not experience early life trauma and 2 (once), 3 (a few times), 4 (many times) were defined as those who experienced early life trauma.
The CIDI questionnaire for evaluating MDD was composed of DSM-IV criteria, and MDD was diagnosed according to the DSM-IV diagnostic criteria based on the evaluation results. In this study, among all participants, those diagnosed with MDD were classified as the MDD group, and those not diagnosed with MDD were classified as the control group.
For continuous variables, age and education year, the mean and standard deviation were presented, and the depression group and the control group were compared through an independent
In order to analyze the risk of developing MDD for early life trauma from various aspects, various types of trauma variables were created. To evaluate the risk of developing MDD for types of early life trauma, reported trauma was classified into five categories: bullying, emotional neglect, psychological, physical, and sexual trauma. In addition, in order to evaluate the overall impact of early life trauma, the group that reported even one trauma was classified into ‘any trauma'. Frequency of early life trauma was classified from ‘no trauma' to ‘5 trauma' according to the number of reported types of bullying, emotional neglect, psychological, physical, and sexual trauma.
For each type and frequency of reported early trauma variables, multivariable logistic regression analysis was performed including all explanatory variables within one model. The risk of developing MDD in adulthood was regressed onto each variables of reported early life trauma adjusted with age, gender, years of education, married status and occupation. For each multivariable logistic regression analysis, Bonferroni correction was conducted to adjust for multiple testing and statistical significance was set at
A chi-squared test was conducted to examine the association between reported early life trauma and the differential symptoms of MDD. Bonferroni correction was conducted to adjust for multiple testing and significance was set at
The sociodemographic characteristics of the study population are presented in
Comparison of the sociodemographic profiles of individuals with and without major depressive disorder (MDD) in participants from the Korean Epidemiological Catchment Area Study in 2016 (KECA-2016) (
Mean age (SD) | 49.78 (17.767) | 47.18 (17.88) | 49.91 (17.75) | 0.027 |
Mean education year (SD) | 12.14 (4.413) | 12.00 (3.99) | 12.15 (4.43) | 0.636 |
Gender (%) | <0.001 | |||
- Female | 2,851 (61.3%) | 165 (76.4%) | 2,686 (60.6%) | |
- Male | 1,801 (38.7%) | 51 (23.6%) | 1,750 (39.4%) | |
Married status (%) | <0.001 | |||
- Married | 2,846 (61.2%) | 105 (48.6%) | 2,741 (61.8%) | |
- Widowed/separated/divorced | 823 (17.7%) | 49 (22.7%) | 774 (17.4%) | |
- Single | 983 (21.1%) | 62 (28.7%) | 921 (20.8%) | |
Occupation (%) | <0.001 | |||
- Full time | 1,650 (35.5%) | 45 (20.8%) | 1,605 (36.2%) | |
- Part time | 443 (9.5%) | 25 (11.6%) | 418 (9.4%) | |
- Unemployed | 854 (18.4%) | 56 (25.9%) | 798 (18.0%) | |
- Not indicated | 1,705 (36.7%) | 90 (41.7%) | 1,615 (36.4%) | |
Type of trauma (%) | ||||
- Bullying trauma | 382 (8.2%) | 51 (23.6%) | 331 (7.5%) | <0.001 |
- Emotional neglect trauma | 440 (9.5%) | 59 (27.3%) | 381 (8.6%) | <0.001 |
- Psychological trauma | 391 (8.4%) | 59 (27.3%) | 332 (7.5%) | <0.001 |
- Physical trauma | 430 (9.2%) | 54 (25.0%) | 376 (8.5%) | <0.001 |
- Sexual trauma | 165 (3.5%) | 23 (10.6%) | 142 (3.2%) | <0.001 |
Frequency of trauma (%) | <0.001 | |||
- No | 3,729 (80.2%) | 117 (54.2%) | 3,612 (81.4%) | |
- Single trauma | 432 (9.3%) | 31 (14.4%) | 401 (9.0%) | |
- Multiple traumas | 491 (10.5%) | 68 (31.5%) | 423 (9.5%) |
Of the 216 individuals with MDD, 23.6 experienced bullying trauma, 27.3 experienced emotional neglect trauma, 27.3 experienced psychological trauma, 25 experienced physical trauma, and 10.6% experienced sexual trauma. Of the 4,36 individuals without MDD classified in the control group, 7.5 experienced bullying trauma, 8.6 experienced emotional neglect trauma, 7.5 experienced psychological trauma, 8.5 experienced physical trauma, and 3.2% experienced sexual trauma. The difference in reported trauma frequency between the depression group and the control group was statistically significant for all types of reported early life trauma.
The association between the type of reported early life trauma and the risk of developing MDD in adulthood is presented in
Results of multivariable logistic regression analysis of risk of developing major depressive disorder for specific types of reported early life trauma in participants from the Korean Epidemiological Catchment Area Study in 2016 (KECA-2016) (
No trauma | |||
Any trauma | 3.693 |
2.771–4.921 | <0.0001 |
No trauma | |||
Bullying trauma | 1.847 |
1.207–2.825 | 0.005 |
Emotional neglect trauma | 1.537 | 0.975–2.422 | 0.064 |
Psychological trauma | 1.885 | 1.154–3.080 | 0.011 |
Physical trauma | 1.666 | 1.072–2.589 | 0.023 |
Sexual trauma | 1.416 | 0.830–2.417 | 0.202 |
The association between the frequency of reported early life trauma and the risk of developing MDD is presented in
Results of multivariable logistic regression analysis of risk of developing major depressive disorder for frequency of reported early life trauma in participants from the Korean Epidemiological Catchment Area Study in 2016 (KECA-2016) (
No trauma | |||
1 Trauma | 2.480 |
1.634–3.762 | <0.0001 |
2 Traumas | 3.695 |
2.345–5.824 | <0.0001 |
3 Traumas | 4.263 |
2.518–7.216 | <0.0001 |
4 Traumas | 4.289 |
2.043–9.003 | <0.0001 |
5 Traumas | 26.033 |
12.152–55.771 | <0.0001 |
The association between the different symptoms of MDD and reported early life trauma is presented in
Comparison of the differential symptoms of major depressive disorder according to the presence or absence of early life trauma in participants reported as major depressive disorder in the Korean Epidemiological Catchment area study in 2016 (KECA-2016) (
Depressed mood | 86 (86.9%) | 113 (96.6%) | 0.008 |
Diminished interest or pleasure | 87 (87.9%) | 96 (82.1%) | 0.236 |
Fatigue or loss of energy | 93 (93.9%) | 111 (94.9%) | 0.766 |
Weight loss or gain, appetite decrease or increase | 88 (88.9%) | 105 (89.7%) | 0.839 |
Insomnia or hypersomnia | 93 (93.9%) | 103 (88.0%) | 0.136 |
Psychomotor agitation or retardation | 78 (78.8%) | 77 (65.8%) | 0.035 |
Worthlessness or guilty feeling | 74 (74.7%) | 81 (69.2%) | 0.370 |
Diminished ability to think or concentrate | 92 (92.9%) | 106 (90.6%) | 0.537 |
Thoughts of death, suicidal ideation, attempt, or plan | 58 (58.6%) | 78 (66.7%) | 0.220 |
We attempted to characterize the relationship between reported early life trauma and MDD using a nationwide community sample of South Koreans. The aim was to identify the effect of reported early life trauma on the presence of MDD and explore the associations between reported early life trauma and the different symptoms of MDD. The bullying trauma during early life was risk factors for developing MDD in adulthood. Although not statistically significant, psychological trauma showed a marginal association with the risk of developing MDD. The risk of developing MDD was increased as the types of reported early life traumas increased. In participants with MDD, although not statistically significant, depressed mood showed a marginal association with reported early life trauma.
Among early life traumas, bullying trauma was the only risk factor for developing MDD in adulthood. These results were meaningful in that there are few studies comparing bullying trauma with other early life traumas. In addition, these results suggested that not only trauma in the family, but also trauma in school or peer relationships had a serious effect on the development of depression (
Bullying trauma in early life had both long-term physical and psychological effects in adulthood (
Although not statistically significant, psychological trauma showed a marginal association with the risk of developing MDD. This result was, in part, consistent with previous findings that psychological abuse was associated with depression (
Unlike previous studies, the insignificant consequences of emotional neglect for developing depression were surprising, given that early life trauma is a significant risk factor for depression. However, not everyone who experiences an early life trauma develops depression in adulthood. Different factors, such as resilience, cognitive function, and emotion regulation ability were shown to mediate the development of MDD from early life trauma (
In this study, we did not find an association between the development of MDD and sexual trauma. In the results for the frequency of each early life trauma, sexual trauma was reported to be relatively lower than other types of early life trauma, which may be the cause of the low association. Previous studies found that sexual trauma severely affected the victims, both psychologically and physically (
The risk of developing MDD was increased as the types of reported early life traumas increased. Individuals exposed to a single form of early life trauma had a high probability of being exposed to other forms of early life trauma (
In participants with MDD, depressed mood showed a marginal association with reported early life trauma. Previous study found that early life trauma was associated with higher levels of somatization in adulthood (
Our study has limitations. First, data were obtained from retrospective reports based on participant memories. Thus, biases in memory, such as recall bias, may have affected the accuracy of the data. Depressed individuals could be more likely to remember negative events from their childhood, known as mood-congruent recall (
Despite these limitations, this study has a strength in that it used a nationwide community sample. In the process of selecting the subjects of the survey, samples were evenly extracted nationwide in order to derive nationally representative results. Results from the Korean representative samples were compared with previous studies, and difference due to cultural factors in Korea was discussed. In addition, strength of this study is that, unlike previous studies, the early life trauma was evaluated separately by type. Through this, each type of early life trauma was comparatively analyzed.
It is important to pay attention to early life trauma to prevent depression. A previous study suggested that social support may moderate the association between early life trauma and poor mental health including depression (
We found that the risk of depression varied with the type and frequency of reported early life trauma. Based on these results, early detection and the appropriate management of early life trauma appear important to preventing progression to depression.
The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.
The studies involving human participants were reviewed and approved by Seoul National University Hospital. The patients/participants provided their written informed consent to participate in this study.
HK contributed to the search for background literature, to writing the original draft of the manuscript, and to reviewing. MP and HP participated in the study design and directed acquisition of the data. MF, DM, and HJJ conceptualized the study and revised the manuscript.
This research was funded by the Korean Ministry of Health and Welfare. This study was supported by a grant from the Korean Mental Health R&D Project, funded by the Ministry of Health & Welfare, Republic of Korea (HL19C0001; PI, HJJ), and by a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (HR21C0885). The Korean Ministry of Health & Welfare and the NRF had no further role in the study design; in the collection, analysis, and interpretation of the data; in writing of the report, or in the decision to submit the study for publication.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.
The authors wish to express their gratitude to 12 local investigators and 147 interviewers.