Journal List > J Korean Med Sci > v.35(47) > 1146240

Song, Rhee, Lee, Kim, Shin, and Ahn: Comparison of Suicide Risk by Mental Illness: a Retrospective Review of 14-Year Electronic Medical Records

Abstract

Background

Korea is one of the countries with the highest rate of suicide, while suicidality is known to be closely related to mental illnesses. The study aimed to evaluate the suicide rates in psychiatric patients, to compare it to that of the general population, and to investigate the differences among psychiatric diagnoses and comorbidities.

Methods

Medical records and mortality statistics of psychiatric patients at Seoul National University Hospital from 2003 to 2017 were reviewed. The standardized mortality ratio (SMR) for suicide was calculated to compare the psychiatric patients with the general population. The diagnosis-specific standardized mortality rate and hazard ratio (HR) were adjusted by age, sex, and psychiatric comorbidity (i.e., personality disorder and/or pain disorder).

Results

A total of 40,692 survivors or non-suicidal deaths and 597 suicidal death were included. The suicide rate among psychiatric patients was 5.13-fold higher than that of the general population. Psychotic disorder had the highest SMR (13.03; 95% confidence interval [CI], 11.23–15.03), followed by bipolar disorder (10.26; 95% CI, 7.97–13.00) and substance-related disorder (6.78; 95% CI, 4.14–10.47). In survival analysis, psychotic disorder had the highest HR (4.16; 95% CI, 2.86–6.05), which was further increased with younger age, male sex, and comorbidity of personality disorder.

Conclusion

All psychiatric patients are at a higher risk of suicide compared to the general population, and the risk is highest for those diagnosed with psychotic disorder.

Graphical Abstract

jkms-35-e402-abf001.jpg

INTRODUCTION

Mental illness is an important risk factor for suicide. Patients with mental illnesses are at three- to twelve-fold greater risk of suicide than the general population.1 In general, psychotic disorder, bipolar disorder, and major depressive disorder are classified as severe mental illnesses (SMI) as they are associated with more severe symptoms and higher risk of suicide compared to other mental illnesses.2 The risk factors for suicide in schizophrenia include sociodemographic factors (age and sex) and clinical factors (depressive symptoms, active hallucinations and delusions, substance abuse).3 Suicide in bipolar disorder is influenced by early onset of the illness, polarity of current episode, episode severity, history of suicide attempts, family history of suicide, and comorbidities.45 For major depressive disorder, both young and elderly patients, male patients, and those who are comorbid with anxiety disorder, substance misuse, or somatic disease are at higher risk of suicide.6 Substance abuse,7 personality disorder, and chronic pain8 are among the most frequent psychiatric comorbidities in suicidal patients, including those who are diagnosed with non-SMI.91011
Suicide is one of the major public health issues in Korea. The one-year incidence of suicide among the general population in Korea was 26.6 cases per 100,000 people in 2018,12 the highest among member countries of the Organization for Economic Co-operation and Development (OECD)—more than twice the OECD average of 11.2.13 Suicide is the fourth most common cause of death in Korea,14 and deaths through self-harm have increased from 2002 to 2015.15 Evidence suggests that suicide in Korea is closely related to mental illness.161718 According to nationwide statistics on the causes of suicide in 2018,19 31.6% of suicide deaths were caused by psychiatric problems. In addition, as per a previous study on suicide attempters visiting an emergency room (ER), psychiatric problems constituted the main cause of suicidal behavior for 62.2% of the suicide attempters.16 Another study on patients referring to the ER due to suicidal attempts revealed that patients with schizophrenia and anxiety/somatoform disorders engaged in more serious suicide attempts compared to patients with other psychiatric disorders, which were closely related to suicide completion.20
The purpose of this study was to compare the risk of suicide of mentally ill people compared to the general population. To the best of our knowledge, although there have been many studies on suicide, no study has yet examined suicide among all psychiatric patients including inpatients, outpatients and those visiting ER in Korea. We hypothesized that differences exist among psychiatric diagnoses and that there are modifying factors such as comorbidities, age, and sex.

METHODS

Participants

All patients who visited the psychiatric outpatient clinic, were hospitalized, or visited emergency departments at least three times at Seoul National University Hospital (SNUH) between March 1, 2003 and December 31, 2017 were recruited in this study. Patients' demographic characteristics at the first visit, date and diagnosis at the latter, and their follow-up data were collected from electronic medical records (EMR) of the hospital. Electronic medical system was implemented in SNUH in 2003, and subsequent medical information could be extracted into processed Excel files through SUPREME (https://supreme.snuh.org), a server that integrates and stores EMR data, and provides patient information that satisfies when a researcher enters conditions. According to the counting system of the hospital administration department, when a patient was hospitalized directly from the emergency department, but discharged on the same day due to withdrawal of consent, the number of visits was counted as two, although no medical care has been given. Thus, to assure the comparability of the data across the sample, only patients who visited thrice or more were included.
We integrated the hospital data extracted as above with the nationwide death data from Statistics Korea. Mortality information reported before December 31, 2017 was extracted from the National Statistical Database through the personal information security team of the hospital. The data were merged with the EMR, excluding social security numbers, in order to protect the participants' personal information. Participants were divided into two groups: suicidal deaths vs. survivors or non-suicidal deaths. The cause of death was assigned following the International Classification of Diseases 10th revision (ICD-10).21 Cases of which the cause of death was coded X60–X84 or Y87.0 were included in suicidal deaths group, as in previous research.2223 Cases without data reporting their death or of which the cause of death was not X60–X84 or Y87.0 were classified in the comparator group, i.e., survivors or non-suicidal deaths.

Diagnosis

The diagnosis used for this study was the patients' main diagnoses after the first visit, as recorded in the EMR. Based on ICD-10, the following eight psychiatric diagnoses groups were considered: psychotic disorder, schizophrenia, schizotypal, and delusional disorders (F20–F29); bipolar disorder, manic episode, or bipolar affective disorder (F30 or F31); depressive disorder, depressive episode, recurrent depressive disorder, or persistent mood (affective) disorders (F32, F33, or F34); unspecified mood disorder or unspecified mood (affective) disorder (F39); anxiety disorder and neurotic, stress-related, and somatoform disorders (F40–F48); sleep disorders or nonorganic sleep disorders (F51 or G47); organic (including symptomatic) mental disorders (F00–F09); and substance-related disorder and mental and behavioral disorders due to psychoactive substance use (F10–F19). In this study, patients were classified as having “other” psychiatric problems when their main diagnosis was not psychiatric illness, but have received psychiatric treatment.
We considered all diagnoses attributed to the patients during the follow-up period and defined comorbidity. The comorbidities considered in this study were personality disorder and pain. Based on their ICD-10 codes, the two categories are as follows: personality disorder (specific or mixed/other) (F60 or F61); and pain, headache, malaise and fatigue, fibromyalgia, complex regional pain syndrome (CRPS) I, and CRPS II (multiple site or upper limb) (R51, R52, R53, M797, M890, G5780, G5881, or G564).

Statistical analysis

Participants were divided into suicidal deaths group vs. survivors or non-suicidal deaths group, and baseline demographic and clinical characteristics of the two groups were compared. The average follow-up duration of all participants was calculated and the mean values of the two groups were compared through t-test. The χ2 test was used to compare the observed difference in the nominal variables between groups, such as age group at first visit, sex, diagnosis, and comorbid personality disorder and pain. The distribution of these characteristics of patients by diagnosis was also investigated regardless of suicide outcome.
We calculated the standardized mortality ratio (SMR) of suicide for comparison with the general population, and the hazard ratio (HR) to compare the risk of suicide by diagnosis within participants. The SMR of suicide was defined as the ratio of the observed suicide deaths to the expected suicide deaths among the participants. The number of expected suicide deaths in the participants was calculated by multiplying person-years at risk and year-, sex- and age group-specific suicide death rates in the Korean population, where age groups were 0, 1–4, 5–9, 10–14, …, 85–89, 90+.24 Person-years at risk was computed based on each participant's follow-up period. Diagnosis-specific SMR was calculated in the same way as the ratio of the number of observed and expected suicides for each diagnosis.
The Cox proportional hazards model was used to investigate the HR of suicidal death for each diagnosis. The age considered in the survival analysis was the age at the first visit. The observation period was from the first visit to death, in case the participants died during the study period. The observation period for the survivors was from the year of the first visit to the end of the study in 2017. As a supplementary analysis, changes in HRs according to four factors in each diagnosis were investigated: age, sex, comorbid of personality disorder, and pain. Within each diagnosis, survival analysis was performed using the Cox proportional hazards model. For convenience, comparison was made between patients younger or older than the mean age of the sample, 47.91 years. All statistical analyses were performed using SPSS version 25.0 for Windows (SPSS Inc., Chicago, IL, USA). P value < 0.05 was considered statistically significant.

Ethics statement

This study was approved by the SNUH Institutional Review Board (H-1807-176-963). Due to our retrospective and non-invasive study design, requirement for informed consent was waived by the review board.

RESULTS

Baseline demographic and clinical characteristics of patients

From March 1, 2003 to December 31, 2017, 67,869 patients visited psychiatric outpatient clinic, were hospitalized in a psychiatric ward, or received psychiatric consultation at emergency department at SNUH, and 41,289 patients did at least three times. Among patients who visited at least thrice, 597 (1.4%) died by suicide (Fig. 1). The mean follow-up period of the study participants was 7.7 years, and the mean follow-up period of survivors or non-suicidal deaths group and suicidal deaths group was 7.7 years and 4.2 years, respectively (t = 23.85, P value < 0.001).
Fig. 1

Flowchart showing the process in which participants are divided into two groups. All psychiatric patients who visited Seoul National University Hospital outpatient, ward, or emergency room from 2003-03-01 to 2017-12-31 were totally 67,868. From them, those who visited less than 3 times were excluded. The National Statistical data was matched, and among the patients with death information, the patient with cause of death code X60–X84 or Y87.0 was classified as a suicidal deaths, otherwise a survivor of suicidal death. Finally, there were 40,692 survivors or non-suicidal deaths, and 597 suicidal death.

jkms-35-e402-g001
As shown in Table 1, the two groups showed statistically significant differences in age, sex, diagnosis at the first visit, and comorbidity of personality disorder. Both groups had the highest rates of suicide in their twenties—25.6% in the suicidal deaths group, and 17.9% in the survivors or non-suicidal deaths group. Male sex was statistically more frequent in the suicidal deaths group compared to the comparator, 53.8% vs. 44.1%. By diagnosis, the highest frequency diagnosis in the suicidal deaths group was psychotic disorder (31.3%), and depressive disorder for the survivors or non-suicidal deaths group (23.6%). As for comorbidity, the proportion of patients with a personality disorder was higher in the suicidal deaths group, though that of patients with chronic pain was similar in both groups.
Table 1

Baseline demographic and clinical characteristics of patients

jkms-35-e402-i001
Characteristics Survivors or non-suicidal deaths (n = 40,692) Suicidal deaths (n = 597) χ2 test P value
Age, yra 46.886 < 0.001
< 20 2,657 (6.5) 56 (9.4)
20–29 7,284 (17.9) 153 (25.6)
30–39 5,730 (14.1) 93 (15.6)
40–49 5,189 (12.8) 61 (10.2)
50–59 6,202 (15.2) 82 (13.7)
60–69 6,567 (16.1) 84 (14.1)
70–79 5,342 (13.3) 57 (9.5)
80–89 1,721 (4.2) 11 (1.8)
Sex 22.462 < 0.001
Male 17,931 (44.1) 321 (53.8)
Female 22,761 (55.9) 276 (46.2)
Diagnosisb 183.126 < 0.001
Psychotic disorder 5,853 (14.4) 187 (31.3)
Bipolar disorder 3,219 (7.9) 68 (11.4)
Depressive disorder 9,607 (23.6) 138 (23.1)
Unspecified mood disorder 1,691 (4.2) 23 (3.9)
Anxiety disorder 5,419 (13.3) 39 (6.5)
Sleep disorder 1,534 (3.8) 17 (2.8)
Organic mental disorder 7,216 (17.7) 71 (11.9)
Substance use disorder 970 (2.4) 20 (3.4)
Other 5,183 (12.7) 34 (5.7)
Comorbidityc
Personality disorder 788 (1.9) 25 (4.2) 15.446 0.001
Pain 1,488 (3.7) 23 (3.9) 0.064 0.800
Values are presented as number (%).
ICD-10 = International Classification of Diseases 10th revision.
aFirst visit age; bDiagnosis was classified based on the ICD-10 coding system; psychotic disorder (F20–F29), bipolar disorder (F30 or F31), depressive disorder (F32, F33, or F34), unspecified mood disorder (F39), anxiety disorder (F40–F48), sleep disorder (F51 or G47), organic mental disorder (F00–F09), and substance-related disorder (F10–F19); cComorbidity is a subdiagnosis and follows the ICD-10 coding system; personality disorder (F60 or F61), and pain (R51, R52, R53, M797, M890, G5780, G5881, or G564).
Table 2 shows the distribution of sex, age at first visit, and comorbidity for each diagnosis. Bipolar disorder had the highest frequency of being comorbid with personality disorders (5.7%). Among patients with unspecified mood disorder, 6.2% were diagnosed with chronic pain, which is the highest proportion among all diagnoses. In the case of substance-related disorder, the ratio of male sex was the highest (72.9%). Patients with psychotic disorder and bipolar disorder first visited at earlier age, whereas most patients with organic mental disorder and sleep disorder tended to make their first visit after reaching middle age. Depressive disorder was evenly distributed across all age groups.
Table 2

Baseline demographic and clinical characteristics of patients according to psychiatric diagnosis

jkms-35-e402-i002
Characteristics Psychotic disorder (n = 6,040) Bipolar disorder (n = 3,287) Depressive disorder (n = 9,745) Unspecified mood disorder (n = 1,714) Organic mental disorder (n = 7,287) Sleep disorder (n = 1,551) Substance related disorder (n = 990) Anxiety disorder (n = 5,458) Other (n = 5,217)
Age, yra
< 20 735 (12.2) 402 (12.2) 409 (4.2) 126 (7.4) 61 (0.8) 61 (3.9) 501 (9.2) 17 (1.7) 401 (7.7)
20–29 2,109 (34.9) 1,169 (35.6) 1,169 (12.0) 317 (18.5) 241 (3.3) 88 (5.7) 1,320 (24.2) 144 (14.5) 880 (16.9)
30–39 1,732 (28.7) 690 (21.0) 1,007 (10.3) 224 (13.1) 269 (3.7) 98 (6.3) 989 (18.1) 192 (19.4) 622 (11.9)
40–49 821 (13.6) 427 (13.0) 1,423 (14.6) 242 (14.1) 340 (4.7) 161 (10.4) 894 (16.4) 217 (21.9) 725 (13.9)
50–59 399 (6.6) 324 (9.9) 2,123 (21.8) 309 (18.0) 766 (10.5) 361 (23.3) 803 (14.7) 231 (23.3) 968 (18.6)
60–69 182 (3.0) 205 (6.2) 2,064 (21.2) 290 (16.9) 1,797 (24.7) 456 (29.4) 591 (10.8) 139 (14.0) 927 (17.8)
70–79 53 (0.9) 65 (2.0) 1,310 (13.4) 168 (9.8) 2,630 (36.1) 271 (17.5) 302 (5.5) 48 (4.8) 552 (10.6)
80–89 9 (0.1) 5 (0.2) 240 (2.5) 38 (2.2) 1,183 (16.2) 55 (3.5) 58 (1.1) 2 (0.2) 142 (2.7)
Male 3,154 (52.2) 1,392 (42.3) 3,197 (32.8) 632 (36.9) 2,851 (39.1) 816 (52.6) 722 (72.9) 2,838 (52.0) 2,650 (50.8)
Personality disorderb 175 (2.9) 187 (5.7) 152 (1.6) 30 (1.8) 29 (0.4) 2 (0.1) 40 (4.0) 93 (1.7) 105 (2.0)
Pain 57 (0.9) 103 (3.1) 509 (5.2) 107 (6.2) 326 (4.5) 11 (0.7) 15 (1.5) 141 (2.6) 242 (4.6)
Values are presented as number (%). The baseline characteristics were counted for each diagnosis regardless of suicide, and the percentage in the diagnosis was calculated.
aFirst visit age; bComorbidity is a subdiagnosis and follows the International Classification of Diseases 10th revision coding system; personality disorder (F60 or F61), and pain (R51, R52, R53, M797, M890, G5780, G5881, or G564).

Standardized mortality rates of suicide for each diagnosis

The observed mortality rate of suicide among the subjects was 5.13-fold higher than the expected rate of the general population (SMR, 5.13; 95% confidence interval [CI], 4.73–5.56). The calculated diagnosis-specific SMRs of suicide were 13.03 (95% CI, 11.23–15.03) for psychotic disorder, 10.26 (95% CI, 7.97–13.00) for bipolar disorder, and 5.69 (95% CI, 4.78–6.73) for depressive disorder. Substance-related disorder, anxiety disorder, and sleep disorder also showed higher suicide rates compared to the general population, their SMR being 6.78 (95% CI, 4.14–10.47), 2.45 (95% CI, 1.91–3.09), and 2.55 (95% CI, 1.49–4.09) respectively, although these disorders are not listed among the SMIs. Organic mental disorders and others revealed SMRs of suicide of 2.79 (95% CI, 1.98–3.81) and 2.49 (95% CI, 1.72–3.48), respectively (Table 3).
Table 3

Diagnosis-specific standardized mortality rates of suicide

jkms-35-e402-i003
Diagnosis SMR (95% CI)
Psychotic disorder 13.03 (11.23–15.03)
Bipolar disorder 10.26 (7.97–13.00)
Substance related disorder 6.78 (4.14–10.47)
Depressive disorder 5.69 (4.78–6.73)
Unspecified mood disorder 4.64 (2.94–6.97)
Organic mental disorder 2.79 (1.98–3.81)
Sleep disorder 2.55 (1.49–4.09)
Other 2.49 (1.72–3.48)
Anxiety disorder 2.45 (1.91–3.09)
SMRs of suicide were defined as the number of suicidal deaths observed in the participants/number of expected deaths by suicide.
SMR = standardized mortality ratio, CI = confidence interval.

Survival analysis using Cox-proportional hazards model

Psychotic disorder had the highest HR of 4.16 (95% CI, 2.86–6.05). The HRs of bipolar disorder, depressive disorder, and unspecified mood disorder were 3.12 (95% CI, 1.83–5.55), 2.34 (95% CI, 1.60–3.42), and 1.92 (95% CI, 1.13–3.26), respectively. Although the order of greater suicide risk among psychiatric diagnoses were similar when compared with SMRs or HRs for most diagnoses, HR of substance-related disorder (3.12; 95% CI, 1.83–5.55) was high, similar to that of bipolar disorder (3.13; 95% CI, 2.07–4.75) (Table 4). HR of organic mental disorder was found to be 1.58 (95% CI, 1.03–2.42). The Kaplan-Meier plot is shown in Fig. 2.
Table 4

Comparison of diagnosis-specific HRs of suicide

jkms-35-e402-i004
Diagnosis HRa (95% CI) P value
Psychotic disorder 4.16 (2.86–6.05) < 0.001
Bipolar disorder 3.13 (2.07–4.75) < 0.001
Substance related disorder 3.12 (1.83–5.55) < 0.001
Depressive disorder 2.34 (1.60–3.42) < 0.001
Unspecified mood disorder 1.92 (1.13–3.26) 0.016
Organic mental disorder 1.58 (1.03–2.42) 0.036
Sleep disorder 1.47 (0.82–2.64) 0.198
Anxiety disorder 1.05 (0.66–1.67) 0.833
Other 1 Reference
The reference is the anxiety disorder and the ratio is adjusted by age, sex, and comorbidity of personality disorder, pain.
HR = hazard ratio, CI = confidence interval.
aHR is calculated for each diagnosis using the Cox proportional hazard model.
Fig. 2

Diagnosis-specific survivor curves for 14 years of follow-up. Fig. 2 is a survival analysis graph visualized the contents of Table 4. The diagnosis with the highest HR was psychotic disorder and psychotic disorder has the lowest survival rate. The next highest HR diagnosis was substance-related disorder and bipolar disorder. The diagnosis with the lowest risk of suicide was the group without a psychiatric diagnosis as the main diagnosis.

HR = hazard ratio.
jkms-35-e402-g002

HRs of suicide according to risk factors

Supplementary Table 1 describes HRs according to combination of risk factors in each diagnosis. Patients with psychotic disorder and bipolar disorder had greater suicide rates when combined with personality disorder (HR, 1.74; 95% CI, 1.16–2.60 and HR, 2.34; 95% CI, 1.10–4.99, respectively). Pain significantly increased the risk of suicide in organic mental disorder (HR, 2.38; 95% CI, 1.16–4.86). Suicide risk for psychotic disorder increased at younger age whereas, for bipolar disorder, suicide risk increased at older age.

DISCUSSION

This study evaluated the risk of suicide in psychiatric patients, comparing with the general population and among different psychiatric diagnoses. Compared to the general population, the risk of suicide in psychiatric patients was 5.13-fold higher. Based on patient's diagnosis, psychotic disorder had the highest risk of suicide, followed by bipolar disorder, substance-related disorder, and depressive disorder.
In this study, standardized suicide mortality ratio was 5.13 for all psychiatric patients, 13.03 for those with a psychotic disorder, and 10.26 for bipolar disorder. Previous studies have reported 10- to 30-fold greater risk of suicide in bipolar disorder compared to the general population,6252627 It is also suggested that the risk of suicide increases by 20–30 folds, when the age, sex, and severity of symptoms are corrected.28 However, in a London study29 that did not correct for disease severity, the bipolar cohort had an SMR of 9.77. This paper argues that the risk of suicide in bipolar disorder is exaggerated in some of the studies. In fact, risks of suicide in bipolar disorder reported in studies varied in a wide range according to a recent systematic review.5
SMR for suicide in schizophrenia also differed depending on the country and the study method. In a Swedish study,30 male patients with schizophrenia had an SMR of 15.7, while female patients had an SMR of 19.7. Another 10-year follow-up study in France31 reported similar numbers: the SMR of male schizophrenia patients was 15.8 and of female patients was 17.7. However, in a Taiwanese study using 12-year data,32 the SMR for suicide in schizophrenia patients was as high as 31.3. The study attributes its dissimilar results to their differences in follow-up periods and standard treatments. Literature suggests that differences between the characteristics of the patient groups included in the study, the characteristics of institution, treatment methods, and patient recruitment period may affect SMRs, and that direct comparison between the SMRs calculated in these studies can be difficult.33 Nevertheless, the finding of which patients with psychotic disorder are at higher risk of suicide compared to those with bipolar disorder is similar in most of previous diagnosis-specific SMRs studies,293031 which has important implications.
Previous studies suggest that patients with psychotic disorder have a high suicide rate because they use more fatal methods of suicide.34 Lack of insight may also result in poor adherence to medication and contribute to increased risk of suicide.35 Indeed, although mental illness is a strong risk factor for suicide, proactive management and appropriate treatment may reduce the risk.36
Organic mental disorder and sleep disorder had higher risk of suicide than anxiety disorder. Organic mental disorders, including dementia, increase the risk of suicide among older people over the age of 70.37 It is suggested that risk of suicidal behavior is increased if treatment does not improve the cognitive abilities in depressed patients with early Alzheimer's dementia.38 Sleep disorder also independently increases the risk of suicide.39 However, in case of anxiety disorder, only post-traumatic stress disorder is a risk factor for suicide40 while other studies even suggest that anxiety may reduce suicidal behavior or impulsivity.41 Increased risk of suicide when pain8 or personality disorder coexists591142 is consistent with previous studies.
Similar to our findings, risk of suicide was increased at early age in psychotic disorder, while at older age in bipolar disorder.243 A small Israeli study44 reported that the risk of suicide in elderly bipolar disorder was high, yet bipolar patients are considered to be at high risk of suicide during their youth.5 As this study considered the age of the first visit, it is difficult to distinguish whether patients have received treatment before their visit and to therefore conclude that these results are for patients who have started treatment after middle age. Nonetheless, there is a possibility of high risk of suicide in elderly bipolar disorder, and further study is needed.
A limitation of this study is the study sample may not represent the study population in Korea, as it was conducted in a single medical institution. Additionally, the age used for analysis in the study is not the age of onset, but the age recorded at the initial visit to the hospital. Therefore, the possibilities of receiving treatment at another hospital before coming to this hospital, and the first visit occurring long after previous onset were not considered. Other sociodemographic factors such as living alone, being divorced, early trauma, and exposure to suicide were not considered in the study.
However, the study has several strengths. This is a 14-year longitudinal study using a large sample size data, which were extracted using the recently developed SUPREME system. Moreover, to our knowledge, this is the first study that investigates the risk of suicide among Korean psychiatric patients compared to the general population. It is also meaningful to state that our study presents both SMRs and HRs, which are considered to be representative values with external and internal validity, by comparing with the general population and between diagnosis within the patient group.
This study found that people with mental illness are at 5.13-fold higher risk of suicide than the general population, and those with a psychotic disorder have the highest risk of suicide, greater than those with bipolar disorder. The risk of suicide can vary depending on age and sex, psychiatric diagnosis, and coexistence of personality disorder or pain. Thus, it is important to assess patients' risk by examining their situations. Such findings should be considered in making health policies for suicide prevention plans for Korean psychiatric patients.

Notes

Funding: This research was supported by a grant of 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 (grant No. HL19C0020).

Disclosure: The authors have no potential conflicts of interest to disclose.

Author Contributions:

  • Conceptualization: Song Y, Rhee SJ, Ahn YM.

  • Data curation: Song Y, Rhee SJ, Ahn YM.

  • Formal analysis: Song Y, Rhee SJ, Ahn YM.

  • Investigation: Song Y, Rhee SJ, Ahn YM.

  • Methodology: Song Y, Rhee SJ, Ahn YM.

  • Software: Song Y, Rhee SJ, Ahn YM.

  • Validation: Song Y, Rhee SJ, Lee H, Kim MJ, Shin D, Ahn YM.

  • Writing - original draft: Song Y.

  • Writing - review & editing: Rhee SJ, Lee H, Kim MJ, Shin D, Ahn YM.

References

1. Sadock BJ, Kaplan HI, Sadock VA. Kaplan & Sadock's Synopsis of Psychiatry: Behavioral Sciences/Clinical Psychiatry. 9th ed. Philadelphia, PA: Lippincott Williams & Wilkins;2003.
2. Osborn D, Levy G, Nazareth I, King M. Suicide and severe mental illnesses. Cohort study within the UK general practice research database. Schizophr Res. 2008; 99(1-3):134–138. PMID: 18155881.
crossref
3. Hor K, Taylor M. Suicide and schizophrenia: a systematic review of rates and risk factors. J Psychopharmacol. 2010; 24(4):Suppl. 81–90. PMID: 20923923.
4. Hansson C, Joas E, Pålsson E, Hawton K, Runeson B, Landén M. Risk factors for suicide in bipolar disorder: a cohort study of 12 850 patients. Acta Psychiatr Scand. 2018; 138(5):456–463. PMID: 30076611.
crossref
5. Plans L, Barrot C, Nieto E, Rios J, Schulze TG, Papiol S, et al. Association between completed suicide and bipolar disorder: a systematic review of the literature. J Affect Disord. 2019; 242:111–122. PMID: 30173059.
crossref
6. Courtet P. Understanding Suicide: from Diagnosis to Personalized Treatment. Cham: Springer;2016.
7. Park SC, Lee SK, Oh HS, Jun TY, Lee MS, Kim JM, et al. Hazardous drinking-related characteristics of depressive disorders in Korea: the CRESCEND study. J Korean Med Sci. 2015; 30(1):74–81. PMID: 25552886.
crossref
8. Kim YE, Park H, Jo MW, Oh IH, Go DS, Jung J, et al. Trends and patterns of burden of disease and injuries in Korea using disability-adjusted life years. J Korean Med Sci. 2018; 34(Suppl):(1):e75.
crossref
9. Mee S, Bunney BG, Bunney WE, Hetrick W, Potkin SG, Reist C. Assessment of psychological pain in major depressive episodes. J Psychiatr Res. 2011; 45(11):1504–1510. PMID: 21831397.
crossref
10. Olié E, Guillaume S, Jaussent I, Courtet P, Jollant F. Higher psychological pain during a major depressive episode may be a factor of vulnerability to suicidal ideation and act. J Affect Disord. 2010; 120(1-3):226–230. PMID: 19394086.
crossref
11. Racine M. Chronic pain and suicide risk: a comprehensive review. Prog Neuropsychopharmacol Biol Psychiatry. 2018; 87(Pt B):269–280. PMID: 28847525.
crossref
12. Central Suicide Prevention Center. The suicide rate in Korea, 2018. Updated 2018. Accessed March 1, 2020. http://spckorea-stat.or.kr.
13. Organisation for Economic Co-operation and Development. OECD health statistics 2017. Updated 2019. Accessed March 1, 2020. http://www.oecd.org/els/health-systems/OECD-Health-Statistics-2019-Frequently-Requested-Data.xls.
14. Statistics Korea. Mortality trend by cause of death. Updated 2020. Accessed March 1, 2020. http://www.index.go.kr/potal/main/EachDtlPageDetail.do?idx_cd=1012.
15. Shin Y, Park B, Lee HA, Park B, Han H, Choi EJ, et al. Disease-specific mortality and prevalence trends in Korea, 2002–2015. J Korean Med Sci. 2020; 35(4):e27. PMID: 31997615.
crossref
16. Kim H, Kim B, Kang SG, Kim MD, Kim MH, Kim SI, et al. Attempted suicides in South Korea: a multi-center analysis of causes, methods, and psychiatric diagnoses of suicidal attempters in 2013. Korean J Biol Psychiatry. 2015; 22(4):187–194.
17. Office for Government Policy Coordination, Prime Minister's Secretariat. State coordination office of Republic of Korea. National action plan for suicide prevention. Updated 2020. Accessed February 6, 2020. http://www.opm.go.kr/opm/info/project02.do.
18. Park E, Choi SJ. Prevalence of suicidal ideation and related risk factors among Korean adults. J Korean Acad Psychiatr Ment Health Nurs. 2013; 22(2):88–96.
crossref
19. Korea Suicide Prevention Center. Cause of suicide. Updated 2020. Accessed July 24, 2020. https://spckorea-stat.or.kr/korea02.do.
20. Lee JS, Choi JW, Park SB, Yoo HI, Hong JP. Preliminary study on the clinical characteristics between suicide attempters and suicide completers who had visited emergency room. J Korean Neuropsychiatr Assoc. 2010; 49(2):185–192.
21. World Health Organization. ICD-10 online versions. Updated 2018. Accessed February 5, 2018. https://www.who.int/classifications/icd/icdonlineversions/en/.
22. Barak-Corren Y, Castro VM, Javitt S, Hoffnagle AG, Dai Y, Perlis RH, et al. Predicting suicidal behavior from longitudinal electronic health records. Am J Psychiatry. 2017; 174(2):154–162. PMID: 27609239.
crossref
23. Räsänen S, Hakko H, Viilo K, Meyer-Rochow VB, Moring J. Excess mortality among long-stay psychiatric patients in Northern Finland. Soc Psychiatry Psychiatr Epidemiol. 2003; 38(6):297–304. PMID: 12799779.
crossref
24. Korea National Statistical Office. Suicide data. Updated 2019. Accessed February 5, 2019. http://kostat.go.kr/portal/korea/index.action.
25. Dome P, Rihmer Z, Gonda X. Suicide risk in bipolar disorder: a brief review. Medicina (Kaunas). 2019; 55(8):E403. PMID: 31344941.
crossref
26. Bauer M, Andreassen OA, Geddes JR, Vedel Kessing L, Lewitzka U, Schulze TG, et al. Areas of uncertainties and unmet needs in bipolar disorders: clinical and research perspectives. Lancet Psychiatry. 2018; 5(11):930–939. PMID: 30146246.
crossref
27. Allgulander C, Allebeck P, Przybeck TR, Rice JP. Risk of suicide by psychiatric diagnosis in Stockholm County. A longitudinal study of 80,970 psychiatric inpatients. Eur Arch Psychiatry Clin Neurosci. 1992; 241(5):323–326. PMID: 1606198.
28. Pompili M, Gonda X, Serafini G, Innamorati M, Sher L, Amore M, et al. Epidemiology of suicide in bipolar disorders: a systematic review of the literature. Bipolar Disord. 2013; 15(5):457–490. PMID: 23755739.
crossref
29. Dutta R, Boydell J, Kennedy N, VAN Os J, Fearon P, Murray RM. Suicide and other causes of mortality in bipolar disorder: a longitudinal study. Psychol Med. 2007; 37(6):839–847. PMID: 17349107.
crossref
30. Ösby U, Correia N, Brandt L, Ekbom A, Sparén P. Mortality and causes of death in schizophrenia in Stockholm county, Sweden. Schizophr Res. 2000; 45(1-2):21–28. PMID: 10978869.
crossref
31. Limosin F, Loze JY, Philippe A, Casadebaig F, Rouillon F. Ten-year prospective follow-up study of the mortality by suicide in schizophrenic patients. Schizophr Res. 2007; 94(1-3):23–28. PMID: 17574389.
crossref
32. Ko YS, Tsai HC, Chi MH, Su CC, Lee IH, Chen PS, et al. Higher mortality and years of potential life lost of suicide in patients with schizophrenia. Psychiatry Res. 2018; 270:531–537. PMID: 30342411.
crossref
33. Armstrong BG. Comparing standardized mortality ratios. Ann Epidemiol. 1995; 5(1):60–64. PMID: 7728286.
crossref
34. Park S, Ahn MH, Na R, Kim SO, Yoon JS, Park JH, et al. Factors associated with suicide method among psychiatric patients in a general hospital in Korea. Psychiatry Res. 2013; 210(3):945–950. PMID: 24055162.
crossref
35. Higashi K, Medic G, Littlewood KJ, Diez T, Granström O, De Hert M. Medication adherence in schizophrenia: factors influencing adherence and consequences of nonadherence, a systematic literature review. Ther Adv Psychopharmacol. 2013; 3(4):200–218. PMID: 24167693.
crossref
36. Kasckow J, Felmet K, Zisook S. Managing suicide risk in patients with schizophrenia. CNS Drugs. 2011; 25(2):129–143. PMID: 21254789.
crossref
37. Erlangsen A, Zarit SH, Conwell Y. Hospital-diagnosed dementia and suicide: a longitudinal study using prospective, nationwide register data. Am J Geriatr Psychiatry. 2008; 16(3):220–228. PMID: 18310552.
crossref
38. Draper B, Peisah C, Snowdon J, Brodaty H. Early dementia diagnosis and the risk of suicide and euthanasia. Alzheimers Dement. 2010; 6(1):75–82. PMID: 20129322.
crossref
39. Bernert RA, Joiner TE. Sleep disturbances and suicide risk: a review of the literature. Neuropsychiatr Dis Treat. 2007; 3(6):735–743. PMID: 19300608.
crossref
40. Cougle JR, Keough ME, Riccardi CJ, Sachs-Ericsson N. Anxiety disorders and suicidality in the national comorbidity survey-replication. J Psychiatr Res. 2009; 43(9):825–829. PMID: 19147159.
crossref
41. Couto T, Neves F, Machado MCL, Vasconcelos AG, Correa H, Malloy-Diniz LF. Assessment of impulsivity in bipolar disorder (BD) in comorbidity with generalized anxiety disorder (GAD): revisiting the hypothesis of protective effect. Clin Neuropsychiatry. 2012; 9(2):102–106.
42. Fishbain DA, Lewis JE, Gao J. The pain suicidality association: a narrative review. Pain Med. 2014; 15(11):1835–1849. PMID: 24995953.
crossref
43. Caldwell CB, Gottesman II. Schizophrenia--a high-risk factor for suicide: clues to risk reduction. Suicide Life Threat Behav. 1992; 22(4):479–493. PMID: 1488792.
44. Aizenberg D, Olmer A, Barak Y. Suicide attempts amongst elderly bipolar patients. J Affect Disord. 2006; 91(1):91–94. PMID: 16434107.
crossref

SUPPLEMENTARY MATERIAL

Supplementary Table 1

Comparison of diagnosis-specific HRs according to age, sex and comorbidity
jkms-35-e402-s001.doc
TOOLS
Similar articles