Suicide among adolescents and young adults is a major public health concern, as rates continue to rise despite increased awareness. Among adolescents and young adults (hereafter referred to as young people), suicide is the second highest cause of death (
1). Since 2007, a 56% increase has been noted in suicide deaths among young people ages 10–24 years (
1). Concern over increasing suicide rates prompted the development of the National Strategy for Suicide Prevention (
2), which focuses on suicide prevention as a core aspect of all health care services. Previous efforts to slow suicide rates have primarily focused on individuals with psychiatric diagnoses within behavioral health settings (
3). The modifiable risk in this population, however, is low, given the relatively small volume of patients who have suicidal intent in these settings (
2). Thus, general medical settings offer an opportunity to expand suicide prevention efforts and address this issue at scale, because most patients who are at increased suicide risk are seen in these settings prior to their death (
4,
5).
Understanding health diagnoses and health care utilization among young people before suicide can help with identification and intervention efforts. To date, however, most studies of suicide risk have focused on adults, either exclusively (
6,
7) or by combining adults and young people in analyses (
4,
5,
8). The few studies that have examined health conditions and health care encounters among young suicide decedents have done so by using subpopulations or specific settings, including Medicaid enrollees (
9), youths in the child welfare system (
10), and young people in the emergency department (ED) (
11,
12). This study sought to expand the knowledge base in this research area by examining these associations among young people ages 10–24 who died by suicide and a matched control group in nine large, geographically diverse health care systems. An investigation of diagnoses of mental and general medical disorders and health care utilization across an array of health care interactions provides an opportunity to identify more avenues to effectively implement suicide prevention measures catered to young people. We hypothesized that mental (including substance use) disorder diagnoses would be associated with increased risk for suicide. Given that nearly half of adults who die by suicide have a mental illness diagnosis, we expected that young people would show a similar prevalence rate. Finally, we anticipated that in the month and year before death, suicide decedents visited the health care system more often than did control group patients.
Results
The overall study population consisted of 4,895 individuals (case group, N=445; control group, N=4,450); 53% (N=2,588) were males, and the mean±SD age was 16.9±4.1 years. As shown in
Table 1, the proportion of males among suicide decedents was significantly greater than in the control group. Age was also significantly associated with suicide death, with a greater proportion of young adults (ages ≥18) among suicide decedents. Patients living in census blocks with low education levels were significantly less likely to be suicide decedents. Insurance type and living in a higher-poverty census block were not significantly associated with suicide death. Data on insurance type were missing for 202 patients, and data for the poverty and education variables were missing for 156 and 1,430 patients, respectively; the two groups did not significantly differ on missingness for these variables. Comparing suicide decedents with and those without a mental or substance use disorder diagnosis, we found that those without such a diagnosis were more likely to be male (53%, N=186 of 349) than female (33%, N=32 of 96), but that they did not differ in other demographic characteristics from those with a substance use disorder diagnosis.
Table 2 provides information on unadjusted conditional regression results examining the association of diagnoses of mental and general medical disorders with the odds of suicide death. Just over half (51%) of suicide decedents had at least one mental disorder diagnosis. Depression (33%), anxiety (20%), substance use disorder (12%), and attention-deficit hyperactivity disorder (ADHD) (11%) were among the most common. Nearly all diagnoses were associated with greater odds of suicide death. Diagnoses associated with the largest ORs included suicidal ideation, psychotic disorders, alcohol use disorder, and any substance use disorder. After adjustment for age and sex assigned at birth, nearly all odds remained the same, with back pain becoming nonsignificant in the adjusted model.
Table 3 shows the results of conditional logistic regressions that examined health care visit subtypes, adjusted for age and sex assigned at birth. Nearly half (42%) of youths in the group of suicide decedents made a health care visit in the month before suicide, and almost all (88%) made a visit within the previous year. Outpatient specialty and primary care visits were the most common and second most common visit type, respectively, in both groups. Visits associated with a mental disorder diagnosis were also common among suicide decedents, with 23% having such a visit in the month before suicide and almost half (48%) in the previous year. Significant group differences were observed for every visit subtype, with suicide decedents being more likely to have a specific encounter than were control group patients. The greatest discrepancies between groups for specific settings were for inpatient stays and ED or urgent care visits, with adjusted ORs ranging from 3.54 to 94.57.
All health care visit subtypes were significantly more frequent among suicide decedents (
Table 4). Young people who died by suicide made on average 11.4 total health care visits in the previous year, compared with 6.5 among the young people in the control group. Outpatient specialty visits were most common among both groups (suicide decedents, 8.1; control group, 4.7). Primary care visits were the second most common visit type: suicide decedents, 3.0; control group, 2.5. The mean number of visits with a mental disorder diagnosis was 4.0 and 0.9 among suicide decedents and control group patients, respectively.
Discussion
In this large, geographically diverse sample of young people seeking care in nine large U.S. health systems, mental and general medical disorders were common among suicide decedents. Depression, anxiety, ADHD, and substance use disorders were the most common among those with a behavioral health diagnosis, highlighting targets for suicide prevention. Of note, nearly half (49%) of suicide decedents lacked a recorded psychiatric diagnosis in the year prior to death, a finding consistent with recent national reports for U.S. adults (
17,
18). Health care visits were also common among suicide decedents; more than one in three (42%) of young people who died by suicide had a health care visit in the month before their death and nearly all (88%) in the previous year, highlighting missed opportunities for providers to intervene in order to reduce suicide risk.
Our results indicated that nearly all mental disorders distinguished young people who died by suicide from those who did not, an observation largely consistent with case-control (
9–
12) and other studies of psychiatric risk factors for suicide-related behavior among youths (
19–
21). Alcohol and other substance use disorders were the most prevalent disorders among the suicide decedents, and the case-control comparisons produced some of the highest ORs for these conditions. Previous studies have reported similar results (
9,
10), indicating that increased substance use screening may have a substantial positive effect on suicide prevention. A notable exception among mental disorders in this study was autism, with no significant difference in this diagnosis between the two groups. However, youths with conditions meeting
ICD-9 diagnostic criteria for autism have a wide range of cognitive and adaptive abilities, ranging from individuals who are unable to verbally communicate to those who are extremely gifted and live independently. The inability to control for this variation may explain the lack of group differences.
Epilepsy and sleep disorders were also significantly associated with increased risk for suicide death. Previous research has noted relationships between suicide-related behavior and chronic general medical disorders (
9,
10), with mixed findings for asthma (
9,
10,
22). Epilepsy, however, has a long-standing association with suicide-related behaviors (
23,
24), including among young people (
9,
10,
22). Previous investigations have also noted that sleep disturbances and insomnia have resulted in increased suicidal ideation (
25), suicide attempts (
26), and deaths (
15) among young people. Although more evidence exists linking sleep problems to both suicidal ideation and suicide attempts, the literature on suicide deaths among those with sleep disorders is limited to psychological autopsy (
15). Our study advances the field by reporting on documented sleep disorders among young suicide decedents.
The health care utilization findings indicated that young people who died by suicide were more likely than their counterparts in the control group to make health care visits in the year before the index date. Our results are similar to those from a recent study of young Medicaid enrollees in which 45% had a health care encounter in the month before death (
9) (42% had an encounter in this study). Our findings are also similar to those in the previous study (
9) in that outpatient visits were the most utilized by suicide decedents while also being associated with the smallest relative odds of suicide. As noted elsewhere (
5), such findings underscore the challenge in providing suicide prevention across all areas of care that include high-volume, lower-odds settings (i.e., outpatient settings) and lower-volume, high-risk settings (i.e., inpatient or ED).
After inpatient stays, use of ED or urgent care was associated with the greatest relative risk for suicide death, particularly when the patient had a mental or substance use disorder diagnosis. ED visits have been found to be common in the year before death by suicide among young people (
27); of note, studies indicate that suicide risk screening is feasible in the ED setting (
28), and patients newly identified as being at high risk could be linked to further services. For a substantial proportion of youths, the ED is the only point of health care contact (
29), making it an essential setting to enact prevention efforts. In the year before dying by suicide, young people had roughly four specialty care visits that were not associated with a mental or substance use disorder diagnosis. Specialty outpatient visits were the most common of all visits, with youths in the group of suicide decedents averaging more than eight visits in the previous year. Brief screeners are feasible to implement in this setting (
30,
31) and may have substantial impact, given the high frequency of such visits by suicide decedents.
The Joint Commission’s recent patient safety goals (
32) recommend suicide risk screening in all health care settings. Patients, however, require follow-up connection to evidence-based services to bend the curve on increasing suicide rates. The Zero Suicide initiative provides a range of evidence-based approaches that are specific to addressing suicide and can be implemented in a variety of settings (
33). Integrated systems can leverage the continuum of Zero Suicide elements, with screening, transition across care settings, and treatment approaches, such as dialectical behavior therapy and collaborative assessment and management of suicidality (
34). Specialty care, primary care, and EDs—settings that may have less capacity for comprehensive service packages—can utilize Zero Suicide strategies that are effective and less resource intensive, such as safety planning (
35), caring contacts (
36), and reduction of lethal means (
37).
Given the strong association of mental disorders with suicide death, it is important to recognize the lack of such diagnoses among half of the suicide decedents. Although suicide can be the result of acute stressors that are not precipitated by a psychiatric diagnosis, many of these young people may have had unrecognized conditions that increased suicide risk. Among suicide decedents, those without a documented mental health condition were more likely to be male, mirroring population-level data (
38); however, suicide decedents without a mental health condition were similar to those with a mental health condition on other demographic factors. The rise in persistent feelings of sadness and hopelessness among young people (
39) necessitates identification of mental health difficulties in all care pathways, such that youths can receive appropriate services before they make a suicide attempt. Many of the mental health conditions linked to increased suicide risk have associated screening instruments that are brief (
40,
41) and may be easily implemented across settings.
Although these findings move the field forward by providing information on health care visits and diagnoses in a large and geographically diverse sample of young people, we note some limitations. The EHR data available for this study did not include information on race and ethnicity. Given the recent escalation of suicidal ideation, suicide attempt, and death among African American youths and youths from other racial and ethnic minority groups (
42,
43), examination of subgroup patterns is essential. We did not have information about this sample on gender identity or sexual orientation, which are factors associated with suicide risk (
44). Indeed, more recent work by our group has highlighted the association between suicide attempts and transgender and gender-diverse individuals (
45). We did not have adequate representation of young people who were uninsured or on Medicaid, compared with their prevalence in national samples; these individuals may have different patterns of health diagnoses and care utilization, compared with those in this study. Although our sample was diverse in many ways, our results may not generalize to other states or to populations with other insurance types. The age range included in our study was broad and may represent different biological, social, or medical risk factors for suicide; however, this range is of practical importance given the eligible age range for several national youth suicide prevention efforts. Funding for this study ended before recent increases in suicide-related behaviors among youths (
39,
46), which are of critical concern. Finally, we did not have information on previous suicide attempts or trauma, known risk factors for future suicide-related behavior.