Psychotic boys performing well in school are at increased risk of suicidal ideation

Authors


  • Medical supervisors: Professor Pirkko Räsänen, Department of Psychiatry, University of Oulu; Professor Jaakko Lappalainen, Department of Psychiatry, School of Medicine, Yale University; Professor Mauri Marttunen, Department of Adolescent Psychiatry, Helsinki University Central Hospital, Peijas; Administrative supervisors: Kaisa Riala, MD, PhD, Taru Ollinen, MD, PhD, and Kristian Läksy, MD, PhD, Department of Psychiatry, Oulu University Hospital; Statistical consultants: Helinä Hakko, PhD, and Kaisa Karvonen, B.Sc, Department of Psychiatry, Oulu University Hospital; Senior researchers: Professor Markku Timonen, Department of Public Health Sciences and General Practice, University of Oulu; Researchers: Essi Ilomäki, MD, Risto Ilomäki, MD, Vesa Tikkanen, medical student, Department of Psychiatry, University of Oulu; Matti Laukkanen, M.Sc, Department of Psychiatry, Oulu University Hospital.

*Kaisa Riala, MD, PhD, Oulu University Hospital, Department of Psychiatry, BOX 26, 90029 OYS, Finland. Email: kaisa.riala@oulu.fi

Abstract

Aim:  This study investigated how the level of school performance is associated with suicidal behavior and psychiatric disorders among adolescent psychiatric inpatients aged 12–17 years.

Methods:  Data were collected from 508 adolescents (300 girls, 208 boys; age 12–17 years) admitted to inpatient psychiatric hospitalization between April 2001 and March 2006. Information on the adolescents' school performance, suicidal ideation, suicide attempts and self-mutilation as well as psychiatric DSM-IV diagnoses was obtained using the Schedule for Affective Disorder and Schizophrenia for School-Age Children.

Results:  An elevated risk of suicidal ideation (OR = 3.6, 95% CI 1.3–10.2, P = 0.017) and of psychotic disorders (OR = 3.2, 95% CI 1.0–10.0, P = 0.048) was observed among male adolescents performing well in school. In addition, adolescents with poor school performance had an increased likelihood of substance-related disorder both in boys (OR = 2.6, 95% CI 1.1–6.1, P = 0.027) and girls (OR = 2.5, 95% CI 1.2–5.1, P = 0.011).

Conclusions:  Our findings indicate that psychotic inpatient male adolescents performing well in school are at an elevated risk of suicidal ideation. Although good school performance is often considered a marker of high intelligence and good general ability, symptoms of major psychiatric disorders and suicidality need to be taken very seriously among adolescents performing well in school.

GOOD SCHOOL PERFORMANCE has rarely been considered a risk factor for suicidality, whereas low cognitive ability and poor school performance have been found to be related to an elevated risk of suicidality in various studies.1–4 For example, in a large Swedish study (n = 987 308) where 18-year-old men's military intelligence test scores were examined in relation to cause of death, a strong linear association was found between the test result and subsequent suicide. For each unit increase in the score of the logic test, the risk of suicide decreased by 12%.5

Controversially, when suicides during compulsory military service in Israel were examined it appeared that the soldiers who committed suicide had significantly higher than average intelligence ratings. Of the total of 43 subjects 70% were frontline soldiers, and their overall functioning was very high.6 Moreover, some studies have reported an increased risk of suicide in psychotic patients with high educational achievements or intellectual functioning in general.7–9 All of these studies have been made with selected study samples including patients from different age groups. In addition, the measuring of subjects' educational achievements or general capacity has also varied a lot. However, recent findings from a large geographical Birth Cohort also suggest that good school performance increases the risk of suicide especially in males suffering from psychotic disorders.10

Among underage adolescents, the relationship between school performance and suicidality has only rarely been assessed.3 Despite the fact that psychiatric disorders, particularly depression, are well-known risks for suicidality, they have rarely been controlled for in previous studies. Secondly, only few studies have focused on the association between school performance and adolescent self-mutilative behavior. The objective of this study was to investigate whether good or poor school performance associates with self-mutilation, suicidal ideation, or suicide attempts among under-aged adolescents with different psychiatric disorders. With our data we were able to use a geographically representative sample of adolescents 12–17 years of age who were carefully examined and subsequently diagnosed with a well-known structurized diagnostic tool, Kiddie-Schedule for Affective Disorders and Schizophrenia for School Aged Children (6–18 years) – present and lifetime version (K-SADS-PL),11 during their psychiatric hospitalization.

METHOD

Subjects

The study sample consisted of psychiatric inpatients aged 12–17 years consecutively admitted to Unit 70 at the Department of Psychiatry, Oulu University Hospital, between April 2001 and March 2006. The catchment area of Unit 70 covers the districts of Oulu and Lapland: all adolescents from this area in need of acute psychiatric hospitalization in a closed ward are initially treated in Unit 70. The data of the present study covered 508 adolescents (208 boys, 300 girls) who had given written informed consent. The age of the adolescent boys (mean 15.4, SD 1.4) did not differ significantly from that of the girls (15.5 years, SD 1.3) (Student's t-test, d.f. = 506, P = 0.480). The study protocol was approved by the Ethics Committee of the Faculty of Medicine, University of Oulu. The subjects were interviewed by their treating physician using the K-SADS-PL, by which psychiatric diagnoses were obtained according to DSM-IV criteria.

Measures of suicidal behavior

The information on suicidal behavior (i.e. self-mutilative behavior, suicidal ideation and suicide attempts) was obtained from K-SADS-PL. Self-mutilative behavior (SMB) was defined to be present when non-suicidal physical self-damaging acts were repetitive (at least four times a year) or had caused serious injury to self. Suicidal ideation was defined to be present when thoughts of suicide had been recurrent and the adolescent had also thought out the method of suicide. Suicide attempts were defined to exist if an adolescent had performed a life-threatening attempt with definite suicide intent or with potentially medically lethal consequences.

In the present study, the adolescents were categorized according to their suicidal behavior to the following exclusive subgroups: (i) Non-suicidal subjects (no SMB, no suicide ideation, no suicide attempts); (ii) SMB adolescents (subjects with SMB, but without suicidal ideation or suicide attempts); (iii) Suicide ideation adolescents (subjects with suicide ideation, but without suicide attempts); and (iv) Adolescents with suicide attempts.

Measures of school performance

The measurement of school performance was based on patients' self-reported mean score of all school subjects in the latest school report or comprehensive school final report. The information was extracted from K-SADS-PL, or if the information was not available from K-SADS-PL, it was completed by information from the European Addiction Severity Index (EuropASI) questionnaire.12 In Finland the marks range from 4 (fail) to 10 (excellent). The level of school performance was assessed using a grade point average and it was categorized, separately for boys and girls, into the following levels: (i) Average school performance (grade point average between the 20th and 80th percentiles of the gender-specific distribution); (ii) Poor school performance (grade point average below the 20th percentile); and (iii) Good school performance (grade point average above the 80th percentile). We preferred to use gender-specific upper (highest 20th percentile) and lower (lowest 20th percentile) quintiles to indicate the most extreme groups for school performance instead of using a fixed cut-off point for grade point average, as there are known to be notable gender differences in the distribution of grade point averages.13

Covariates

Family type during the admission to the psychiatric hospital, school information on repeated grade(s) and special services in school as well as information on adolescents' regular smoking was obtained from the K-SADS-PL. Family type was categorized as follows: (i) Two-parent family (two biological parents), (ii) single-parent family (one biological parent) or (iii) other family type (e.g. adoptive/foster families, grandparents, residential placement). Repeated grade(s) (no, yes) refer to an adolescent having had to repeat a school year at least once. Special services (no, yes) in school indicates that the adolescent had received special education or had been in a special class in school. Regular daily smoking (no, yes) means that the adolescent smokes at least one cigarette per day.

Psychiatric diagnoses

All DSM-IV-based current psychiatric diagnoses of the adolescents were obtained using the K-SADS-PL. The psychiatric diagnoses were categorized into five major groups: (i) Substance-related disorders (DSM-IV: 303.9, 304.0–.6, 304.8–.9, 305.0, 305.2–.7, 305.9); (ii) Anxiety disorders (300.00–.02, 300.21–.23, 300.29, 300.3, 308.3, 309.81); (iii) Affective disorders (296.2–.3, 300.4, 311); (iv) Conduct or oppositional defiant disorders or Attention-Deficit Hyperactivity Disorder (312.8–.9, 313.81, 314.00–.01, 314.9, 299.80); and iv) Psychotic disorders (295, 296.0, 296.4–9, 297.1–3, 298.8–9, 301.13, 301.22). The psychiatric diagnoses of the adolescents were overlapping, that is, a patient might have several types of psychiatric diagnoses.

Statistical methods

Statistical significance of group difference in categorical variables was assessed with Pearson's χ2 test. A logistic regression analysis was used to examine the association of school performance with suicidal behavior and psychiatric disorders after adjusting for covariates. The significance level (two-tailed) of 0.05 was employed in all statistical tests. The statistical software used in the analyses was SPSS version 13.0.

RESULTS

Demographic characteristics

The demographic characteristics of the male and female adolescents are listed in Table 1. Boys were more rarely living with two biological parents. In addition, adolescent boys had more commonly repeated grade(s) and received more special services in school than girls. Girls had statistically significantly more suicide ideation and attempts than boys. Of psychiatric disorders, affective and anxiety disorders prevailed among girls, while conduct disorders were more common among boys. No gender difference was observed in regular daily smoking and the prevalence of substance-related disorders.

Table 1.  Demographic characteristics of the male and female study subjects
VariableBoys (n = 208)Girls (n = 300)Gender difference
n%n%χ2
  1. *P < 0.05; **P < 0.01; ***P < 0.001. SMB, self-mutilative behavior.

Family type    14.77**
 Two biological parents5727.413244.0 
 One biological parent7134.18428.0
 Other family type8038.58428.0
Regular daily smoking    0.91
 No5526.49130.0 
 Yes15373.620969.7
Repeated grade(s) in school    21.54***
 No/not known15574.527090.0 
 Yes5325.53010.0
Special services in school    19.99***
 No/not known7837.517357.7 
 Yes13062.512742.3
Suicidal behavior    2.69***
 Non-suicidal13866.311144.6 
 SMB104.8237.7
 Suicide ideation3416.38829.3
 Suicide attempts2612.57826.0
Substance-related disorders    1.49
 No12258.719264.0 
 Yes8641.310836.0
Affective disorders    20.19***
 No13564.913444.7 
 Yes7335.116655.3
Anxiety disorders    10.84**
 No17483.721371.0 
 Yes3416.38729.0
Conduct disorders    27.81***
 No8641.319565.0 
 Yes12258.710535.0
Psychotic disorders    2.05
 No18187.027391.0 
 Yes2713.0279.0

School performance and suicidal behavior

When comparing the level of school performance of non-suicidal adolescents with that observed in subjects with SMB, suicidal ideation or suicide attempts, the only statistically significant difference was seen in boys having suicidal ideation. While 17 (15.6%) of the boys with normal and 5 (15.6%) with poor school performance had suicidal ideation, the corresponding proportion was 11 (40.7%) in boys with good school performance (χ2 = 9.1, d.f. = 2, P = 0.011).

In further analyses, logistic regression analysis was used to assess the association between school performance and suicidal behavior after controlling for age, family type, repeated grades and special services in school, regular daily smoking and current DSM-IV diagnosed psychiatric disorders of the adolescents. As reported in Table 2, only good school performance of the adolescent boys was shown to be associated with suicidal ideation (OR = 3.6, 95% CI = 1.3–10.2). In this logistic model, statistically significant covariates were affective disorders (OR 10.3 95% CI 3.7–28.7; P < 0.001) and psychotic disorders (OR 6.7 95% CI 2.0–22.6; P = 0.002). Interestingly, a trend was noted between good school performance and increased SMB among boys (OR 4.1 95% CI 0.8–20.3). In adolescent girls, no significant association was observed between any categories of suicidal behavior or any level of school performance.

Table 2.  Association between school performance and self mutilative behavior (SMB), suicide ideation and suicide attempts in a clinical sample of adolescents aged 12–17 years from northern Finland
 Non-suicidalSMB (but not suicide ideation or attempts)Suicide ideation (but not suicide attempts)Suicide attempts
n (%)n (%)Adj. OR (95% CI)P-valuen (%)Adj. OR (95% CI)P-valuen (%)Adj. OR (95% CI)P-value
  • A logistic regression model predicting the likelihood of SMB, suicide ideation and suicide attempts (each compared to non-suicidal subjects) with school performance and the following covariates: age, regular daily smoking, family type, repeated grade(s) and special services in school as well as depressive, anxiety, conduct, psychotic and substance-related disorder of the adolescents.

BOYS          
 School performance          
 Average (ref.)92 (68.1)6 (60.0)ref. 17 (51.5)ref. 16 (69.6)ref. 
 Poor (20th percentile)27 (20.0)1 (10.0)0.6 (0.1–5.2),0.6255 (15.2)0.9 (0.3–2.7)0.7913 (13.0)0.5 (0.1–1.9)0.325
 Good (80th percentile)16 (11.9)3 (30.0)4.1 (0.8–20.3)0.08711 (33.3)3.6 (1.3–10.2)0.0174 (17.4)2.1 (0.6–7.8)0.275
GIRLS          
 School performance          
 Average (ref.)65 (59.6)13 (61.9)ref. 60 (69.0)ref. 46 (62.2)ref. 
 Poor (20th percentile)20 (18.3)6 (28.6)0.9 (0.3–2.8)0.81913 (14.9)0.6 (0.2–1.5)0.25914 (18.9)0.7 (0.3–1.8)0.425
 Good (80th percentile)24 (22.0)2 (9.5)1.1 (0.2–6.7)0.88614 (16.1)0.6 (0.2–1.4)0.21414 (18.9)1.0 (0.4–2.5)0.985

School performance and psychiatric disorders

Figure 1 presents the prevalence of psychiatric diagnoses in each school performance category. Among male adolescents school performance was shown to be associated statistically significantly with substance use disorders and psychotic disorders. Substance use disorders were shown to be more common in boys with poor school performance (n = 22, 61.8%) than in boys with good (10, 29.4%) or normal (52, 39.7%) school performance (χ2 = 7.9, d.f. = 2, P = 0.019). On the contrary, psychotic disorders were more often observed in boys with good school performance (9, 26.5%) than in boys with poor (4, 11.1%) or normal (13, 9.9%) levels of school performance (χ2 = 6.7, d.f. = 2, P = 0.035). The results remained the same after controlling for covariates in a logistic regression model. Compared to boys with normal school performance, an increased likelihood for substance-related disorders was seen in adolescent boys with poor school performance (OR 2.6, 95% CI 1.1–6.1, P = 0.027) and for psychotic disorders in adolescent boys with good school performance (OR 3.2, 95% CI 1.0–10.0, P = 0.048).

Figure 1.

Distribution of psychiatric diagnoses in different groups of school performance among adolescents in a clinical sample of psychiatric inpatients from northern Finland.

Among female adolescents school performance was statistically significantly associated with substance-related disorders as well as with conduct disorders. A higher prevalence of substance-related disorders was found in adolescent girls with poor school performance (33, 62.3%) compared to girls with normal (61, 33.2%) or good (10, 19.5%) school performance (χ2 = 23.7, d.f. = 2, P < 0.001). Similarly, conduct disorders were more prevalent in girls with poor school performance (28, 52.8%) than in girls with normal (63, 34.2%) or good (9, 16.7%) school performance (χ2 = 15.5, d.f. = 2, P < 0.001). When adjusting for covariates in a logistic regression model, an increased likelihood of substance-related disorders was seen in girls with poor school performance (OR 2.5, 95% CI 1.2–5.1, P = 0.011).

DISCUSSION

In our data comprising adolescent psychiatric inpatients aged 12–17 years, we found that the likelihood of suicidal ideation was elevated among males performing well in school. There was a more than threefold risk of suicidal ideation among boys with good school performance. Compared to other diagnostic groups, boys with psychotic disorders performing well in school reported suicidal ideation more commonly.

For suicide attempts, no significant associations were found in this study. However, it has to be kept in mind that suicidal ideation is known to be a predictor of future suicide attempts14 and therefore we consider our finding important. Furthermore, self-mutilative behavior has earlier been described to differ clearly from other types of suicidal behavior as there are several other motives for self-mutilation, such as coping with stress, punishing oneself and showing one's desperation.15 In our study, the preliminary notion that boys performing well in school might be at risk of SMB deserves further research.

Good school performance as a risk factor for suicidal ideation in male patients with psychotic disorders is a novel finding among underage adolescents. In an earlier study by Drake and co-workers,7 high educational achievements and awareness of illness or insight were found to be risk factors for completed suicide in an adult schizophrenia inpatient sample. We think that the increase in suicidal ideation among those performing well in school could be partly due to higher intelligence and higher relative change in general ability as well as higher fear and awareness of mental illness as a threat to their future success in life. Unfortunately and as a limitation to our study, we did not have measures of intelligence. Future studies should assess both school performance and intelligence and their relation to suicidality in different psychiatric diagnostic groups.

Prodromal symptoms of psychotic disorders, such as social isolation, impairment in personal hygiene and peculiar behavior and symptoms of depression might result in introvert and less assertive behavior. Those who have prodromal symptoms and perform well in school could be more susceptible to bullying than average-performing peers. As being bullied at school is known to be strongly associated with suicidal ideation,16 in our opinion our finding of increased suicidal ideation among psychotic boys performing well in school could partly be explained by this link. An earlier finding by Campell and colleagues also suggests that being bullied in school may contribute to the development of psychotic disorder.17

Methodological considerations

The findings of this study should be considered in the light of the following weaknesses: Firstly, our sample consisted of selected inpatient population, and therefore the results cannot be applied to the general population. Secondly, we were not able to utilize a mentally healthy reference population so as to draw conclusions on an epidemiological level. Thirdly, intelligent people suffering from psychotic disorders may also be able to hide their suicidal ideas and their psychotic symptoms.18 This may result in underdiagnosing and underestimating suicidal ideation among those performing well in school. Fourthly, it is already known that boys have higher rates of completed suicide because of the use of more violent methods.19 This may result in fewer hospitalized male attempters and, in our study, to putative underestimation regarding boys' suicide attempts and their association with school performance.

Clinical implications

Our findings indicate that psychiatric inpatient boys performing well in school seem to be at an elevated risk of suicidal ideation. Despite the fact that good school performance is often considered a marker of high intelligence and good general ability, symptoms of major psychiatric disorders and suicidality need to be taken very seriously, especially in adolescents performing well in school.

ACKNOWLEDGEMENTS

This study received support from the Päivikki and Sakari Sohlberg Foundation, Ethel F. Donaghue Women's Health Investigator Program at Yale, Alcoholic Beverage Medical Research Foundation (ABMRF), VA MIRECC, the Alma and K.A. Snellman Foundation and Yrjö Jahnsson Foundation.

We also thank the staff of the adolescent Unit 70 of the Oulu University Hospital for data collection, and all the adolescents who participated in this study.

Project registered: http://www.medicine.oulu.fi/psyk/sivut/tutkimus.htm

Ancillary