Background
Juvenile offenders constitute 5.1% of all criminal offenders in South Korea. Approximately 8272 juvenile offenders are newly detained in juvenile detention centers every year [
1]. Previous studies reported that 40–90% of juvenile offenders had at least one psychiatric disorder [
2‐
6], which represents an approximately three- to fourfold higher prevalence of psychiatric illness compared with the general population [
7‐
9]. The prevalence of different psychiatric disorders varies by study; in a metaregression analysis of 13,778 boys and 2972 girls, 3.9–7.3% of the boys had major depression, 4.1–19.2% had attention deficit hyperactivity disorder (ADHD), and 40.9–64.7% had conduct disorder. Among the girls, 21.9–36.5% had major depression, 9.3–27.7% had ADHD, and 32.4–73.2% had conduct disorder [
10].
Despite the high rate of psychiatric illnesses among juvenile offenders, research on the psychiatric health of this population in Asian countries, including South Korea, is limited. Park et al. [
1] reported that, among 1700 inmates of three prisons, 28.1% were classified as being at high risk for depression, 33.6% had suicidal ideation, and 39.1% were diagnosed with alcohol abuse. Another study reported higher rates of depression, paranoia, antisociality, and Minnesota Multiphasic Personality Inventory (MMPI) scale hypomania among 1155 juvenile offenders compared to the general population [
11]. Both studies used self-rated questionnaires, and only the latter targeted a juvenile population. To our knowledge, no South Korean study has estimated the prevalence of psychiatric disorders among juvenile offenders using Diagnostic and Statistical Manual for Mental Disorders (DSM) or International Classification of Diseases (ICD)-based criteria.
Conduct disorder is one of the most common psychiatric disorders among juvenile offenders, with the prevalence ranging from 31 to 77% [
12,
13]. In previous studies, conduct disorder showed high comorbidity with substance use disorders and ADHD; all of these disorders are risk factors for higher psychiatric disorders.
The purpose of this study was to investigate the prevalence of psychiatric disorders among juvenile detainees in South Korea, and to assess patterns of comorbidity and psychopathology among those with conduct disorder.
Results
The demographic and judicial characteristics of the whole sample, and of the detainees with and without conduct disorder, are presented in Table
1. The mean age was 17.5 ± 1.1 years, and all participants were male. In total, 42 (24.3%) of the participants had dropped out of school, and 104 (60.1%) were from a family with a yearly income exceeding $2500. A majority of the detainees had been living in a single parent home (n = 97, 56.1%), and 57 (32.9%) had been living with both parents; 19 (11.0%) had not been living with their parents. Property crime was the most common type of crime (n = 86, 49.7%), followed by violent crime (n = 68, 39.3%), traffic offenses (n = 42, 24.3%), and sex crimes (n = 34, 19.7%).
Table 1
Demographic and clinical characteristics of the detainees with and without conduct disorder
Age (years), mean (SD) | 17.5 (1.1) | 17.4 (1.2) | 17.6 (1.1) | 0.171 |
School drop out, N (%) | 42 (24.3) | 23 (24) | 19 (24.7) | 0.913 |
Yearly family income > $2500, N (%) | 104 (60.1) | 59 (61.5) | 45 (58.4) | 0.687 |
Paternal education ≥ college education, N (%) | 25 (14.5) | 13 (19.1) | 12 (21.4) | 0.750 |
Maternal education ≥ college education, N (%) | 20 (11.6) | 10 (16.7) | 10 (18.2) | 0.830 |
Living arrangements, N (%) | | | | 0.928 |
With both parents | 57 (32.9) | 31 (32.3) | 26 (33.8) | |
With a single parent | 97 (56.1) | 55 (57.3) | 42 (54.5) | |
No parents | 19 (11.0) | 10 (1.4) | 9 (11.7) | |
Recidivism, N (%) | 154 (89) | 88 (91.7) | 66 (85.7) | 0.213 |
Number of crime, mean (SD) | 3.2 (1.8) | 3.4 (1.9) | 3.1 (1.6) | 0.243 |
Type of crime, N (%) |
Property crime | 86 (49.7) | 48 (49) | 40 (51.9) | 0.696 |
Violent crime | 68 (39.3) | 48 (50) | 20 (26) | 0.001 |
Sex crime | 34 (19.7) | 14 (14.6) | 20 (26.3) | 0.055 |
Drug crime | 1 (0.6) | 0 (0) | 1 (1.3) | 0.445 |
Domestic violence | 1 (0.6) | 1 (1.0) | 0 (0) | 1.00 |
Traffic offenses | 42 (24.3) | 23 (24.0) | 19 (24.7) | 0.913 |
Obstruction of justice | 7 (4.0) | 4 (4.2) | 3 (3.9) | 1.00 |
Drunk driving | 2 (1.2) | 2 (2.1) | 0 (0) | 0.503 |
Others | 20 (11.6) | 13 (13.5) | 7 (9.1) | 0.363 |
There were no significant differences between the groups with versus without conduct disorder in demographic or judicial characteristics, except for a higher rate of violent crimes in the conduct disorder group (p = 0.001; Table
1).
Data on psychiatric disorder prevalence and comorbidity with conduct disorder are shown in Table
2. In total, 157 (90.8%) participants had at least one psychiatric diagnosis, and the most common axis I psychiatric disorder was alcohol use disorder (n = 100, 57.8%), followed by conduct disorder (n = 96, 55.5%), bipolar disorder (n = 82, 47.4%), and ADHD (n = 61, 35.3%). Antisocial personality traits were present in 83 (48%) detainees.
Table 2
Prevalence of psychiatric disorders among detainees and comorbidity with conduct disorder
Any psychiatric disorder, except conduct disorder | 154 (89.0) | 93 (96.9) | 61 (79.2) | <0.001 |
Number with diagnosis, N (%) |
Major depressive disorder | 50 (28.9) | 41 (21.9) | 9 (11.7) | 0.079 |
Bipolar disorder | 82 (47.4) | 59 (61.5) | 23 (29.9) | <0.001 |
Alcohol use disorder | 100 (57.8) | 66 (68.8) | 34 (44.2) | 0.001 |
Substance use disorder | 8 (4.6) | 4 (4.2) | 4 (5.2) | 1.00 |
Schizophrenia | 19 (11.0) | 11 (11.5) | 8 (10.4) | 0.823 |
Eating disorder | 6 (3.5) | 6 (6.3) | 0 (0) | 0.026 |
ADHD | 61 (35.3) | 40 (41.7) | 21 (27.3) | 0.049 |
Tic disorder | 47 (27.2) | 24 (25.0) | 23 (29.9) | 0.474 |
ODD | 14 (8.1) | 0 (0) | 14 (18.2) | <0.001 |
Antisocial personality trait | 83 (48.0) | 62 (64.6) | 21 (27.3) | <0.001 |
Anxiety disorder | 44 (25.4) | 30 (31.3) | 14 (18.2) | 0.050 |
In total, 96 (55.5%) detainees had a diagnosis of conduct disorder, of whom 93 (96.9%) had at least one comorbid axis I psychiatric disorder. Detainees with conduct disorder had a higher rate of comorbidity compared to those without (p < 0.001), and the most common axis I comorbid disorder was alcohol use disorder (n = 66, 68.8%), followed by bipolar disorder (n = 59, 61.5%) and ADHD (n = 40, 41.7%). All of the psychiatric disorders—except for major depressive disorder, substance use disorder, tic disorders, and anxiety disorders—were more frequently diagnosed in the conduct disorder than in the non-conduct disorder group (all p < 0.05).
The detainees with conduct disorder showed significant associations with emotional abuse [odds ratio (OR) = 1.26, 95% confidence interval (CI) 1.06–1.43; p = 0.009], sexual abuse (OR = 1.23, 95% CI 1.03–1.46; p = 0.022), and physical abuse (OR = 1.23, 95% CI 1.06–1.43; p = 0.008), and all associations remained significant after adjusting for age, living arrangements, socioeconomic status, and the presence of psychiatric comorbidities (Table
3).
Table 3
Association of childhood maltreatment and conduct disorder
Child maltreatment | 136 (78.6) | 76 (79.2) | 60 (77.9) | 1.019 | 0.849–1.223 | 0.843 | 1.01 | 0.82–1.24 | 0.942 |
Type of childhood maltreatment |
Emotional abuse | 54 (31.2) | 38 (39.6) | 16 (20.8) | 1.257 | 1.059–1.492 | 0.009 | 1.252 | 1.04–1.51 | 0.018 |
Sexual abuse | 49 (28.3) | 34 (35.4) | 15 (19.5) | 1227 | 1.029–1.462 | 0.022 | 1.209 | 1.00–1.46 | 0.048 |
Physical abuse | 87 (50.3) | 57 (59.4) | 30 (39.0) | 1.230 | 1.055–1.434 | 0.008 | 1.271 | 1.07–1.51 | 0.006 |
Emotional neglect | 92 (53.2) | 49 (51.0) | 42 (55.8) | 0.953 | 0.820–1.108 | 0.529 | 1.370 | 0.70–2.70 | 0.364 |
Physical neglect | 93 (53.8 | 49 (51.0) | 44 (57.1) | 0.940 | 0.809–1.093 | 0.424 | 0.934 | 0.79–1.10 | 0.418 |
Scores on YSR subscales were higher in the conduct disorder versus non-conduct disorder group, including total problem behavior (β = 1.57, 95% CI 0.47–2.67; p = 0.005), externalizing behavior (β = 2.33, 95% CI 1.27–3.40; p < 0.001), somatic complaints (β = 0.58, 95% CI 0.01–1.16; p = 0.047), rule-breaking behavior (β = 1.41, 95% CI 0.78–2.03; p < 0.001), and aggressive behavior (β = 1.15, 95% CI 0.45–1.85; p = 0.001) after adjusting for age and the presence of psychiatric comorbidities (Table
4).
Table 4
Association of YSR scores with conduct disorder
Total problem behavior | 57.2 (14.2) | 49.9 (13.3) | 1.57 | 0.47 to 2.67 | 0.005 |
Internalizing | 51.6 (13.4) | 46.6 (12.9) | 1.034 | −0.10 to 2.08 | 0.052 |
Externalizing | 65.6 (13.5) | 55.3 (13.5) | 2.332 | 1.27 to 3.40 | <0.001 |
Anxious/depressed | 55.3 (7.5) | 53.6 (6.3) | 0.39 | −0.16 to 0.95 | 0.166 |
Withdrawn/depressed | 55.4 (7.3) | 54.0 (6.4) | 0.26 | −0.29 to 0.81 | 0.353 |
Somatic complaints | 56.1 (8.2) | 53.7 (5.7) | 0.581 | 0.01 to 1.16 | 0.047 |
Thought problems | 56.2 (7.9) | 53.8 (6.0) | 0.553 | −0.1 to 1.12 | 0.055 |
Attention problems | 55.6 (7.5) | 53.9 (8.0) | 0.35 | −0.27 to 0.97 | 0.261 |
Rule-breaking behavior | 69.7 (7.4) | 63.5 (8.6) | 1.41 | 0.78 to 2.03 | <0.001 |
Aggressive behavior | 59.6 (10.0) | 54.5 (7.1) | 1.15 | 0.45 to 1.85 | 0.001 |
Discussion
Research on the prevalence of psychiatric disorders among detained adolescents is still limited in comparison to analogous research in adults. Nevertheless, reports of psychiatric prevalence studies of adolescents have been published with increasing frequency over the past few years.
The main objectives of this study were to document the rate and distribution of comorbidities, severity of childhood maltreatment, and clinical characteristics of adolescents with conduct disorder detained in a juvenile detention center in South Korea.
Many of the juvenile offenders in our study had psychiatric disorders, including alcohol use disorder, conduct disorder, bipolar disorder, and ADHD. The percentage of detainees with at least one psychiatric axis I disorder was 90.8%, which is very high compared to the rates reported among the general adolescent population, and is in the range reported in previous studies. Alcohol abuse (57.8%) was the most common disorder, followed by conduct disorder (55.5%), bipolar disorder (47.4%), and ADHD (35.3%). Additionally, antisocial personality traits were identified in 48% of the participants. Previous studies have shown that personality disorder is highly prevalent in incarcerated juvenile populations [
25]. However, a diagnosis of antisocial personality disorder is still possible above 18 years of age if there is evidence of conduct disorder with an onset prior to 15 years of age; thus the term ‘trait’ was used rather than ‘disorder’. These findings are similar to the results of Collins et al., in that the mean prevalence of any disorder was 69.9% (95% CI 69.5–70.3), with conduct disorder occurring most frequently (46.4%; 95% CI 45.6–47.3), followed by substance use disorder (45.1%; 95% CI 44.6–45.5), oppositional defiant disorder (19.8%; 95% CI 9.2–20.3), and ADHD (13.5%; 95% CI 13.2–13.9) [
26]. In a meta-analysis by Fazel et al., high rates of psychotic illness (male adolescents, 3.3%), major depression (10.6%), ADHD (11.7%), and CD (male adolescents, 52.8%) were described [
10]. Despite methodological differences between the two studies, overall prevalence rates for ADHD (Fazel et al., 11.7%, compared with 13.6% in our study), CD (52.8% vs. 38.8%), and major depression (10.6% vs. 10.0%) were similar [
10]. As expected, conduct disorder was the most prevalent of the disorders studied, with a similar prevalence in both sexes of slightly more than 50% [
10]. A report by the American Academy of Pediatrics estimated the prevalence ranges as follows: 1–6% for psychosis, up to 50% for ADHD, and 20–60% for conduct disorder [
27]. Thus, the risk of conduct disorder is five to tenfold higher than that of the general population [
10].
Another finding of the current study was that the rate of violent crimes among the conduct disorder group was higher than that of the non-conduct disorder group. Out of a total of 96 (55.5%) detainees who had a diagnosis of conduct disorder, 93 (96.9%) had at least one comorbid axis I psychiatric disorder. Those with conduct disorder had a higher rate of comorbidities than those without, and the most common axis I comorbid disorder was alcohol use disorder, followed by bipolar and ADHD. With the exceptions of major depressive disorder, substance use disorder, tic disorders, and anxiety disorders, all psychiatric conditions were more frequently diagnosed in the conduct disorder than in the non-conduct disorder group. One main implication arises from these findings: mental disorders are markedly more common among adolescents in detention than among age-equivalent individuals in the general population. The largest increase in risk among detainees is for conduct disorder; for male adolescent detainees, the risk of conduct disorder is five- to tenfold higher than that of the general population [
10].
Regarding the YSR subscales, including total problem behavior, externalizing behavior, somatic complaints, rule-breaking behavior, and aggressive behavior, after adjusting for age and the presence of psychiatric comorbidities, scores for the conduct disorder group were consistently higher. No significant differences were found on the other subscales, including internalizing behavior, anxious/depressed behavior, withdrawn/depressed behavior, thought problems, and attention problems, after adjusting for age and the presence of psychiatric comorbidities. Additionally, Rosenblatt et al. [
28] reported that juvenile offenders displayed increased functional impairment due to conduct and externalizing behavioral problems compared to the general adolescent population.
Although conduct disorder is a psychiatric condition commonly observed among juvenile detainees in South Korea, available psychiatric interventions of for this population remain limited. The present results confirm that detainees with conduct disorder had higher rates of comorbid axis I psychiatric disorders and violent crime perpetration, and had suffered more physical, emotional, and sexual abuse than those without conduct disorder. These findings suggest that the diagnosis of, and interventions for, conduct disorder within the juvenile detention system are important for the prevention of further damage to juvenile detainees.
The present study also demonstrated that detainees with conduct disorder had more severe psychopathologies than those without conduct disorder; thus, designing intervention programs will be necessary. Furthermore, additional research on the treatment of youth detainees with conduct disorder will be necessary. Subsequent studies aimed at identifying the traits of youth detainees with conduct disorder, such as callous unemotional traits, may lead to the development of more effective treatments for juvenile detainees with these characteristics.
There were some noteworthy limitations to this study. First, we included only male subjects, as the juvenile detention center from which the participants were drawn was for males only; this may limit the generalizability of the findings. Second, the detainees without conduct disorder also had high rates of psychiatric comorbidity, and there were insufficient detainees without a psychiatric disorder to act as a control group for the conduct disorder detainees. Therefore, further studies including control groups (which could be detainees without any psychiatric disorder or adolescents drawn from the general population) could help to clarify the results. Third, because we conducted the study inside the detention center, the detainees were the only informants and we were unable to obtain information from any other source. Fourth, rather than the MINI KID, the MINI was used to diagnose psychiatric disorders. The use of an adult assessment tool may be a limitation in that it does not fully cover child and adolescent psychiatric diagnoses. Finally, the detainees were drawn from a single detention center; further large-scale studies including detainees from other areas and detention centers are thus warranted.
Authors’ contributions
BSC, JIK, BNK and BK were responsible for study concept and design. BK contributed to the acquisition of data. BSC and JIK were involved in the interpretation of the data. BSC was responsible for drafting the manuscript, and all authors were involved in critical revisions of the manuscript. All authors read and approved the final manuscript.