Background
Suicidal behavior (SB) is a major issue for mental health workers and often a cause of emergency treatment and psychiatric hospitalization. It also requires our special attention since it is usually seen as a salient sign of a high risk of suicide [
1]. Psychiatric disorders have been ascertained to be a major causative factor for SB [
1‐
3], and the treatment is expected to play an important role in reducing SB recurrence and preventing suicide [
1].
A number of clinical investigations of suicidal patients have been conducted in medical or emergency service settings, which have increased our body of knowledge of the patient population, and improved our psychiatric practice for treating them. In contrast, the number of studies that have addressed suicidal patients admitted to a psychiatric hospital remains insufficient though these two patient populations are not identical, and may need to be treated differently. Only a portion of suicidal patients treated in medical or emergency settings were referred for psychiatric hospitalization [
4‐
6]. It has also been asserted that suicidal patients admitted to psychiatric facilities exhibit characteristics that differ from those of patients who are primarily in need of medical treatment [
4,
7]. Therefore, investigation of the former group patients is needed to improve the treatment for them. In addition, this patient population should be an important target of studies since having both an SB experience and a history of psychiatric hospitalization are considered to be strong predictors of suicide [
1,
8,
9].
To remedy the situation, we conducted extensive psychiatric evaluation of suicidal patients admitted to a psychiatric center in a metropolitan area of Japan by applying structured interviews. In the evaluation, we included the clinical characteristics that were dealt with as factors in theories of a pathway to suicide process [
10,
11], on the basis of which we previously showed a potential role of some pre-SB characteristics in the development of SB [
12]. In the present study, we attempt to illuminate the clinical characteristics of this patient sample and their gender and age-relevance.
Results
Of a total of 3450 admissions to Tokyo Metropolitan Matsuzawa Hospital during the 20-month study period, 292 cases (280 patients) with SB were identified. 225 patients fulfilled the criteria (1)-(4). 157 (69.8%) of them (and their family guardian when necessary) gave consent to participate in the study, and 155 (68.9%) of them completed the assessment. 127 (81.9%) of the subjects were involuntarily admitted. The average (SD) duration of the period between admission and completion of the assessment was 25.7 (12.0) days.
There was no significant difference in ICD-10-based diagnoses in the hospital record or demographic and clinical characteristics presented in Table
1 between the subjects of this study and the 50 patients who were approached, but did not gave informed consent.
Table 1
Demographic and clinical characteristics of the subjects
Age at investigation (years) | | | | | | |
20-29 | 22 | 32.4 | 25 | 28.7 | 47 | 30.3 |
30-39 | 23 | 33.8 | 37 | 42.5 | 60 | 38.7 |
40-49 | 13 | 19.1 | 13 | 14.9 | 26 | 16.8 |
50+ | 10 | 14.7 | 12 | 13.8 | 22 | 14.2 |
Marital state | | | | | | |
Never married | 48a
| 70.6 | 39 | 44.8 | 87 | 56.1 |
Cohabiting with spouse or partner | 11 | 16.2 | 26 | 30.0 | 37 | 23.9 |
Living alone | 34b
| 50.0 | 58 | 66.7 | 92 | 59.4 |
Education | | | | | | |
Less than high school | 19 | 27.9 | 25 | 28.7 | 44 | 28.4 |
High school graduate | 32 | 47.1 | 49 | 56.3 | 81 | 52.3 |
University (college) graduate | 17 | 25.0 | 12 | 13.8 | 29 | 18.7 |
Unemployed | 42 | 61.8 | 40 | 46.0 | 82 | 52.9 |
Referred after inpatient treatment for physical damage | 14 | 20.6 | 8 | 9.2 | 22 | 14.2 |
Currently on psychiatric treatment | 54 | 79.4 | 72 | 82.8 | 126 | 81.3 |
History of psychiatric hospitalization | 38 | 55.9 | 52 | 59.8 | 90 | 58.1 |
Family history of mental disorderc
| 18 | 26.9 | 34 | 39.1 | 52 | 33.8 |
Family history of attempted or committed suicided
| 10 | 14.7 | 16 | 18.4 | 26 | 16.9 |
Table
1 shows the demographic and clinical characteristics of the subjects. The subjects consisted of 68 males and 87 females. Their average age (SD) was 36.5 (11.9) years old. 49 subjects (31.6%) started to exhibit SB at an age of 20 years or younger. The rates of unemployment and living alone were over 50%.
Table
2 shows the most frequent SBs that were exhibited by the subjects. The proportions of other SBs immediately prior to admission were lower than 3.3%. Over 60% of subjects had previously exhibited self-cutting and overdosing. The 25, 50 and 75 percentiles (range) of the total number of SBs in the lifetime history of the subjects were 3, 7 and 19 (1-141), respectively. The following associations of SBs with gender and age were found in the analyses where a significance level of 0.01 (0.05/5) was applied since statistical tests were conducted for each of the 5 SB methods shown in Table
2. The numbers of self-cutting and overdosing the subjects had experienced were greater for female subjects than for males (medians, ranges of females and males: 3, 0-132 and 1, 0-50 (p = 0.008, U = 2232.5, z = -2.67) and 2, 0-90 and 1, 0-100 (p = 0.003, U = 2142.5, z = -3.02), respectively). The number of self-cutting experiences had a significant negative rank-order correlation with age at investigation (-0.252, p = 0.002).
Table 2
Frequent suicidal behaviors (SBs) of the subjectsa
Self-cutting | 63 | 40.6 | 106 | 68.4 | 1 | 0-132 |
Wrist or forearm | 41 | 26.5 | 96 | 61.9 | 1 | 0-100 |
Other part(s) of body | 28 | 18.1 | 42 | 27.1 | 0 | 0-70 |
Overdosing | 49 | 31.6 | 99 | 63.9 | 2 | 0-100 |
Prescribed psychotropics | 43 | 27.7 | 95 | 61.3 | 1 | 0-100 |
Other prescribed medicine | 4 | 2.6 | 5 | 3.2 | 0 | 0-30 |
OTC medicine | 8 | 4.5 | 14 | 9.0 | 0 | 0-6 |
Self-strangulation | 23 | 14.8 | 37 | 23.9 | 0 | 0-20 |
Hanging | 12 | 7.7 | 25 | 16.1 | 0 | 0-20 |
Other self-strangulation | 11 | 7.1 | 13 | 8.4 | 0 | 0-10 |
Jumping from a height | 18 | 11.6 | 45 | 29.0 | 0 | 0-13 |
Attempting traffic death | 16 | 10.3 | 27 | 17.4 | 0 | 0-20 |
6 DSM-IV axis I disorders and 10 axis II PDs of the subjects are exhibited in Tables
3 and
4. Affective disorders and anxiety disorders were presented by more than half of the subjects. It was found in the analysis that applied a significance level of 0.0083 (0.05/6) that subjects with anxiety disorders were younger than those without them (medians, ranges of the age: 32, 20-72 and 36, 21-76, respectively (p = 0.005, U = 2194.5, z = -2.78)). Most of the subjects had at least one PD. Borderline PD was the most frequent PD, and was exhibited by over 50% of the subjects. The analysis that applied a significance level of 0.005 (0.05/10) indicated that PDs, patients with which were younger than those without that PD were borderline PD and antisocial PD (medians, ranges of the age: 32, 20-55 and 39, 20-76 (p < 0.001, U = 1923.5, z = -3.76), and 31, 20-43 and 36, 20-76 (p = 0.002, U = 1606.5, z = -3.09), respectively).
Table 3
DSM-IV Axis I disorders of the subjectsa
Mood Disorders | 36 | 52.9 | 60 | 69.0 | 96 | 61.9 |
Major Depressive Disorders | 28 | 41.1 | 39 | 44.8 | 67 | 43.2 |
Dysthymic Disorder | 0 | 0.0 | 5 | 5.7 | 5 | 3.2 |
Bipolar I Disorder | 3 | 4.4 | 6 | 6.9 | 9 | 5.8 |
Bipolar II Disorder | 4 | 5.9 | 8 | 9.2 | 12 | 7.7 |
Anxiety Disorders | 28b
| 41.2 | 58 | 66.7 | 86 | 55.5 |
Panic Disorders | 16 | 23.5 | 37 | 42.5 | 53 | 34.2 |
Specific Phobia | 4 | 5.9 | 10 | 11.5 | 14 | 9.0 |
Social Phobia | 3 | 4.4 | 6 | 6.9 | 9 | 5.8 |
Obsessive-Compulsive Disorder | 7 | 10.3 | 6 | 6.9 | 13 | 8.4 |
Posttraumatic Stress Disorder | 6 | 8.8 | 19 | 21.8 | 25 | 16.1 |
Generalized Anxiety Disorder | 4 | 5.9 | 11 | 12.6 | 15 | 9.7 |
Substance-Related Disorders | 24 | 35.3 | 35 | 40.2 | 59 | 38.1 |
Alcohol Use Disorders | 15 | 22.1 | 29 | 29.9 | 41 | 26.5 |
Non-alcohol Use Disorders | 12 | 17.6 | 16 | 18.4 | 28 | 18.1 |
Psychotic Disorders | 22 | 32.4 | 19 | 21.8 | 41 | 26.5 |
Schizophrenia | 18 | 26.5 | 13 | 14.9 | 31 | 20.0 |
Schizoaffective Disorder | 3 | 4.4 | 0 | 0.0 | 3 | 1.9 |
Brief Psychotic Disorder | 1 | 1.5 | 5 | 5.7 | 6 | 3.9 |
Eating Disorders | 2 | 2.9 | 12 | 13.8 | 14 | 9.6 |
Anorexia Nervosa | 0 | 0.0 | 2 | 2.3 | 2 | 1.3 |
Bulimia Nervosa | 2 | 2.9 | 6 | 6.3 | 9 | 5.2 |
Eating Disorder NOS | 0 | 0.0 | 4 | 4.6 | 4 | 2.6 |
Somatoform Disorders | 0 | 0.0 | 7 | 8.0 | 7 | 4.5 |
Table 4
DSM-IV personality disorders (PDs) of the subjectsa
Borderline PD | 28b
| 41.2 | 58 | 66.7 | 86 | 55.5 |
Avoidant PD | 21 | 30.9 | 28 | 32.2 | 49 | 31.6 |
Antisocial PD | 22 | 32.4 | 20 | 23.0 | 42 | 27.1 |
Obsessive-compulsive PD | 10 | 14.7 | 24 | 27.6 | 34 | 21.9 |
Paranoid PD | 13 | 19.1 | 16 | 18.4 | 29 | 18.7 |
Schizoid PD | 15 | 22.1 | 10 | 11.5 | 25 | 16.1 |
Narcissistic PD | 7 | 10.3 | 11 | 12.6 | 18 | 11.6 |
Dependent PD | 9 | 13.2 | 8 | 9.2 | 17 | 11.0 |
Schizotypal PD | 5 | 7.4 | 7 | 8.0 | 12 | 7.7 |
Histrionic PD | 3 | 4.4 | 8 | 9.2 | 11 | 7.1 |
Any PD | 55 | 80.9 | 80 | 92.1 | 135 | 87.1 |
The proportions of the subjects who reported each of 3 domains of RLEs and LPs were RLEs and LPs in close relationships 69.7% and 60.0%, those in life-situation 61.9% and 63.2% and those in health conditions 18.1% and 52.9%, respectively. The proportions of those who reported discord or conflict, separation and death in close relationships were 62.6%, 22.6% and 9.0%, respectively. The following associations were found in the analysis that applied a significance level of 0.0167 (0.05/3). Female subjects reported RLEs and LPs in close personal relationships more frequently than males (Chi square = 10.91, df = 1, p = 0.001 and Chi square = 10.48, df = 1, p = 0.001, respectively). Those who reported life-situational RLEs or LPs were younger than those who did not (medians, ranges: 32, 20-69 and 36, 21-76 (p = 0.005, U = 2065, z = -2.83) and 32, 20-69 and 39, 21-76 (p = 0.001, U = 1866.5, z = -3.44), respectively).
The average (SD) of SIS suicidal intent scores was 11.7 (6.1). The proportion of subjects with high suicidal intent according to the criterion used by Skogman, et al. [
6] (suicidal intent score > 18) was 13.5%. Alcohol and drug ingestion before SB occurred in 14.8% and 9.1% of the subjects, respectively. SIS alcohol and drug ingestion scores had a negative rank-order correlation with age at investigation (-0.316, p < 0.001 and -0.236, p = 0.003, respectively).
The averages (SDs) of BDI and BHS scores were 30.5 (12.3) and 13.1 (4.8), respectively. The proportions of depressive symptom severity levels based on BDI were minimal (0-9 points) 5.8%, mild (10-16 points) 8.4%, moderate (17-29 points) 29.7% and severe (30-63 points) 56.1%. Those of hopelessness severity levels based on BHS were mild (4-8 points) 14.8%, moderate (9-14 points) 35.5% and severe (15-20 points) 45.8%.
The averages (SDs) of the 3 OAS-M domain scores: aggression, irritability and medical lethality scores were 5.9 (7.0), 3.5 (2.8) and 1.8 (1.3), respectively. The average of the medical lethality score was almost "mild (2)". The analysis that applied a significance level of 0.0167 (0.05/3) indicated that the irritability score had a negative rank-order correlation with age at investigation (-0.246, p = 0.002). The average (SD) of the PDEQ score was 11.2 (7.1). The proportion of the subjects with any threshold dissociation symptom was 91.6% (142/155).
A history of any abuse before the age of 18 years was reported by 60.6% (94/155) of the subjects. The proportions of those who had experienced the 4 types of abuse were sexual abuse 16.8% (26/155), physical abuse 36.1% (56/155), verbal abuse 51.0% (79/155) and neglect 17.4% (27/155). It was found in the analysis that applied a significance level of 0.0125 (0.05/4) that sexual abuse was more common among female subjects than among males (24.1% (21/87) and 7.4% (5/68), respectively (p = 0.008, Exact test)).
Discussion
Obviously, it is a characteristic of the studied sample that most of the patients had a psychiatric treatment history prior to index admission. The percentages of those who had currently been continuing outpatient treatment and those who had a history of psychiatric hospitalization were over 80% and over 50%, respectively while in the previous studies of suicidal patients in emergency settings, the proportions of those who had been receiving psychiatric treatment before admission were 50-69% [
5,
25,
26]. The next noteworthy feature was a high proportion (over 80%) of the subjects who had a history of SB repetition. The figure was higher than those in previous studies of patients with suicide attempts or deliberate self-harm (DSH) [
27] ranging from 25% to 65% [
5,
6,
25,
26,
28,
29]. In contrast, their physical conditions were not poor before admission as the lethality of their SB was typically mild, and only a small portion of the subjects (14%) received inpatient treatment for physical damage caused by SB.
The average age of the subjects of this study (37 years) was within the range of the previous studies in medical or emergency settings (26-42 years) [
5,
6,
26,
28‐
33]. The excess of female patients over males observed in this study was also common in previous studies [
5,
6,
25,
28‐
32]. High proportions of unemployment and living alone were also indicated as was in the review of Welch [
33].
The SB methods recorded in this study were markedly different from those in the previous studies. Those in this study consisted of a variety of types, mainly not life-threatening ones such as self-cutting and overdosing while previous studies in medical settings reported that overdosing was the most common SB with ranges of 81-96% for DSH [
29,
31] and 29-93% for suicide attempts [
5,
25,
26,
32]. In particular, this study reported a higher rate of self-cutting than those in previous studies, which recorded rates of 4-12% for DSH [
29,
31] and 4-28% for suicide attempts [
5,
25,
26,
28].
The proportions of Axis I disorders found in the present study were not markedly different from the results from previous studies on suicide attempts [
30] and DSH [
29] that applied a structured diagnostic interview, and recorded affective disorders, substance-related disorders and anxiety disorders as major disorders. Exceptions were relatively high rates of psychotic disorders and anxiety disorders in this study. The excess of psychotic disorders could simply be explained by the fact that the field of this study was a psychiatric hospital. In contrast, the proportion of anxiety disorders higher than a little more than 20% of the previous studies that applied structured diagnostic interviews [
29,
30] might be specific of this study, and deserves further examination in new samples of psychiatric suicidal patients.
Concerning the PDs of SB patients, the importance of borderline and antisocial PDs has been emphasized [
34] as this study sample showed high rates of both PDs. 2 previous studies reported a comparable rate of borderline PD among SB patients. Herpertz [
35] reported that 52% (28/54) of inpatients that had exhibited more than 2 SBs had borderline PD. Söderberg [
36] found that the proportion of borderline PD was 55% (35/64) among hospitalized suicidal patients by applying SCID-II. However, the studies of Haw, et al.[
29,
37], which used Personality Assessment Schedule as a self-report scale, showed only a low proportion (11%) of ICD-10 emotionally unstable PD, a subtype of which corresponds to DSM-IV borderline PD. On the other hand, the rate of antisocial PD in this study was comparable to that of Beautrais, et al. [
30], and greater than those of Haw, et al. [
29] and Söderberg [
36]. These differences might be derived from the varied severity of psychiatric disorders among the samples in addition to the methodological diversity of PD assessment.
As in previous studies in medical settings [
31,
37,
38], it was determined in this study that depressive symptoms are clinically important for suicidal psychiatric patients. The BDI and BSH scores were equal to or greater than those of previous studies [
31,
37]. The suicidal intent of the studied sample was within the range of those in previous studies [
5,
32,
37].
The proportions of the studied subjects who reported RLEs and LPs were also comparable to those of previous studies on DSH patients [
31,
38] and on those who have attempted to commit or actually committed suicide [
17,
18] for the most part with the exception of a high percentage of perceived problems in mental health among subjects in this study. The previous studies [
17,
18,
31,
38] reported that the rate of SB- or suicide-preceding RLE or LP in close personal relationships was approx. 60%, and other major RLEs or LPs were those associated with occupation, financial conditions and physical health.
This study showed an association between troubles in the workplace or school before SB and younger age. Several studies [
38‐
40] also reported that suicide or SB by young persons was frequently preceded by RLE in close personal relationships, lawsuits and troubles in the workplace or school. It is suggestive of life-cycle-relevance of SB-preceding RLEs and LPs that these troubles are common among young suicidal patients. However, the link reported by Haw, et al. [
38] between an older age and experiencing physical difficulties was not observed in this study. In terms of gender difference in LPs, this study indicated that females more frequently experienced problems in close personal relationships as in the study of Haw, et al. [
38].
Developmental factors, such as childhood and adolescent abuse, are assumed to have an influence on subsequent SB [
41]. In this study, the proportion of suicidal patients that had experienced abuse at a young age was within the range of those in Japanese studies on various SB samples [
12] while the figure was generally lower than those of the studies conducted in Western countries [
41].
Lastly, limitations of this study need to be mentioned. First, this study is a retrospective and cross-sectional investigation, and is therefore hardly of use for determining causative factors or sequential processes of SB development. In particular, recall biases in evaluations concerning life-history factors such as abuse are inevitable. Second, PD diagnoses in this study, although based on a full application of SCID-II, could be improved. For instance, the PD diagnoses of this study were not exempted from the influence of coexisting axis I disorders that Zimmerman [
42] pointed out. However, we consider that this influence is not so detrimental since the SCID-II was conducted after the subjects had recovered sufficiently to undergo extensive investigation.
Competing interests
The authors declare that they have no competing interests.
Authors' contributions
NH conceptualized and designed the study, collected the data, performed the statistical analysis, and drafted the manuscript. MI, AI, YO, KU, YI, TT and KI conceptualized and designed the study, collected the data. HH, YT, NK, MN and YO conceptualized and designed the study. HI performed statistical analysis. All authors read and approved the final manuscript.