Suicide is the second leading cause of death in youths in the United States, responsible for 6,732 deaths, or 19.7% of all deaths, in youths 10–24 years of age in 2019 (
1,
2). Rates of adolescent suicide, which were stable from 2000 to 2007, increased steadily between 2007 and 2018 (
3,
4).
Risk Factors for Suicide in Youths
Mental health providers aiming to reduce the morbidity and mortality of suicidal thoughts and behaviors in individuals of any age group focus on understanding risk factors that are correlated with suicide. A risk factor may be a stable, nonmodifiable marker that designates an individual or group of individuals as one that will benefit from interventions or more close monitoring or a modifiable direct target of intervention to reduce death by suicide.
Prior Suicide Attempt and Self-injury
It may seem obvious that having suicidal thoughts and behaviors is a risk factor in an individual for death by suicide. As an extension of this principle, a history of prior suicide attempts is perhaps the most fundamental piece of information to gather for a patient of any age in whom safety is being assessed, as it seems to increase the risk of death by suicide by more than any other factor, perhaps between 10-fold and 60-fold (
5). Besides assessment for the presence or absence of a prior suicide attempt, the details of and circumstances surrounding an individual’s prior suicide attempts may provide important clues to prevent a subsequent lethal attempt. Suicide with a firearm and by hanging are considered especially lethal.
Research suggests that individuals who make medically serious suicide attempts are at particularly high risk for subsequent death by suicide (
6). However, those who attempt suicide by less lethal means may initially overestimate the lethality of their chosen method but choose more lethal means for a subsequent attempt, increasing the risk of death.
Nonsuicidal self-harm behavior is a somewhat less dramatic but still robust predictor of future suicide attempts. For instance, meta-analyses have found that nonsuicidal self-injurious behavior increased the likelihood of a suicide attempt in adolescents and young adults (odds ratio=2.26), as well as in all adults (odds ratio=4.27) (
7,
8).
Psychiatric Disorders as Risk Factors for Suicide in Youths
Meta-analyses of individuals of all ages who died by suicide indicate that mental disorders were prevalent, affecting approximately 87% of individuals (based on aggregated data of 3,275 deaths by suicide between 1987 and 2002), and 82% of youths (115 out of 140 youths ages 13–19 in a study of deaths by suicide in Western Pennsylvania) (
9,
10, 11). Of note, psychosis is particularly highly associated with likelihood of suicide attempts; a study of Irish adolescents found an odds ratio of 67.5 for having an acute suicide attempt within 12 months among those experiencing psychotic symptoms (
12). Mood disorders, eating disorders, anxiety disorders, substance use disorders, and attention-deficit hyperactivity disorder (ADHD)—particularly when comorbid with other psychiatric disorders—also confer an elevated risk. For this reason, a review of past diagnoses and a psychiatric review of symptoms, including specifically asking about psychosis, is part of any assessment of suicide risk.
Marginalized Groups
Transgender, gender-diverse, and sexual-orientation-minority youth populations are at significantly elevated risk for suicide. In 2017, the Youth Risk Behavior Survey of high school students found that students who identified as transgender reported a sixfold increased prevalence of suicide attempts; and between 2015 and 2017, students who identified as lesbian, gay, or bisexual had increases of between threefold and 5.5-fold in prevalence of suicide attempts compared with their heterosexual peers (
13–
15).
Although suicide has increased across racial and ethnic groups in the United States, this increase has been more pronounced in Black youths and indigenous youths (
16,
17). Additionally, there is evidence that preadolescent children who are Black are at especially high risk compared with other preadolescent children; the incidence rate ratio of death by suicide for Black children ages 5–12 was 1.82, indicating a rate of suicide that is approximately two times higher in Black preadolescent children (
18). Stigma, socioeconomic factors (such as high rates of poverty and living in areas of concentrated poverty among Black youths), ongoing racial trauma, and other effects of a long history of anti-Black racism and discrimination are all likely factors (
17).
Experience with youths from marginalized groups indicates that experiences that exacerbate their marginalization (racism, homophobia, transphobia, etc.) are often a factor in suicidal ideation and suicide attempts. Reducing suicide risk among these individuals may depend on finding ways to increase inclusion and equity and ways to reduce the psychological toll of marginalization.
Family History
Individuals with relatives who attempted suicide or died by suicide are more likely to attempt suicide or die by suicide. This increased risk is partly explained by an increased risk of psychiatric disorders that confer an increased risk of suicide. It is not fully clear whether family history increases risk of suicidal ideation or whether it increases the risk of acting on suicidal thoughts when they occur (
19). The familial transmission of suicidal behavior has some genetic component, as reported in data from adoption and twin studies, and an increased likelihood of impulsive aggression, or a tendency to react with hostility or aggressive behavior in response to circumstances, seems to be an intermediate phenotype for transmission of suicidal behavior (
20,
21).
Other Risk Factors
A history of trauma and adversity is a significant risk factor for suicide. In one study, a lifetime history of abuse was especially highly correlated with death by suicide in male youths, with an odds ratio of 49.3 (
11). In a matched case-control study of youths in the child welfare system, individuals who died by suicide were more likely than controls also in the child welfare system to have been placed outside of the home and to have been diagnosed as having mental health conditions or chronic physical health conditions (
22).
Presence of firearms in the home greatly increases the risk of death by suicide in youths, because choosing this method of suicide, when it is available, results in very high mortality. The odds ratio of death by suicide was found to be between 4.5 and 7.2 in youths when there was a gun in the home (
11).
Acute stressors associated with interpersonal conflict and loss, such as the breakup of a relationship or conflict within the family, increase the risk of suicide (
23). Bullying is also a risk factor associated with suicide in youths, whether the individual is the victim or the perpetrator (
24).
There is an association between exposure to suicidal events and subsequent suicidal behavior. The spread of suicidal behavior after a death by suicide is sometimes referred to as contagion and has implications for schools and communities who lose an adolescent to suicide (
25). Evidence suggests that adolescents experiencing concomitant negative life events together with exposure to suicide are at increased risk (
26).
Exposure to antidepressants as a risk factor for suicidal thoughts and behavior in youths has been an area of interest since an advisory committee of the Food and Drug Administration detected a higher cumulative risk of spontaneously reported suicidal thinking or behavior in youths taking antidepressants in controlled clinical trials compared with those taking placebo. Data from more recent trials and subsequent analyses have demonstrated that, if antidepressants confer risk of suicidal thoughts and behaviors, it is likely smaller than originally feared and is more nuanced (
27,
28). For instance, a meta-analysis of youths with anxiety disorders found that the risk of suicidal thoughts and behaviors was increased with paroxetine but decreased with sertraline when compared with placebo (
29). Although the risk of suicidal thinking or behavior, as well as the risk of mania or hypomania, appears low, patients and families should be informed about the issue when antidepressant medication is started or dosage is increased (
27).
Developmental Considerations
Younger children die by suicide at a much lower rate than adolescents and young adults (
2). The transition from preadolescence to adolescence is generally understood to confer significantly increased risk of both suicidal thoughts and suicidal behavior
(30). However, a nationally representative sample of 11,875 preadolescents found the rate of suicidal ideation in preadolescents to be 14.33% and the rate of suicide attempts to be 1.26%. Identifying as a sexual minority and having a psychiatric disorder—especially two or more psychiatric disorders—increased the risk of suicidal ideation. Male sex also increased the risk of suicidal ideation in preadolescents, which stands in contrast to adolescents and adults, where males have lower rates of suicidal ideation and suicide attempts but higher rates of death by suicide than females (
31–
33).
A study analyzing the circumstances of 134 younger children (ages 5–11) who died by suicide found that these children most commonly died by suffocation or hanging in their bedroom, with death by firearm being the second leading cause of death (
34). Among those in the study who died by firearm, all obtained a gun that had been stored unsafely in the home.
Although the presence of a psychiatric disorder is a risk factor for death by suicide among age groups, research suggests that this risk factor is more important for older adolescents than for younger individuals (
11). For instance, one study found that 60%, or 21 out of 35, of adolescents below age 16 who died by suicide had diagnosed psychiatric disorders in contrast to 82%, or 115 out of 140, of all youths who died by suicide (
10,
11).
Protective Factors
Characteristics in youths that are protective against suicide include a general sense of connectedness. Specifically, parent connectedness, connectedness to other adults, caring friends, participation in sports, academic achievement, and a fondness for school are associated with lower risk of suicidal behavior (
35). Some youths are more likely to seek support from peers than adults, and when this peer support is strong and encourages healthy behaviors, this can be protective. Involvement with organized religion and private religious practices are associated with less suicidal ideation in youths (
36).
Screening for Youth Suicide Risk
Preventing suicide requires both the capacity to detect indicators of suicide risk through screening and a strategy to evaluate those at risk to determine acuity so that urgent action can be taken when it is needed. Clinical pathways for suicide risk screening in youths have been developed for emergency department and inpatient medical settings and have been adapted to outpatient medical settings (
37,
38). To detect suicide risk in individuals who do not present with psychiatric chief complaints, the clinical pathway utilizes universal screening with the Ask Suicide-Screening Questions tool (ASQ), a set of four to five yes–no questions that can be administered in about 20 seconds (
39). Patients who answer “no” to all four initial questions on the ASQ are considered to have a negative screen, and no further assessment is warranted. Patients answering “yes” to any of the first four items are asked a fifth “acuity” question: “Are you having thoughts of killing yourself right now?” Those answering “yes” to the fifth question are considered to have an acute positive screening and need an immediate safety assessment by a qualified individual. Those answering “no” to the fifth acuity item but “yes” to any of the first four items are determined to have a “nonacute positive” screening result and require further assessment, such as with a tool known as the “brief suicide safety assessment” or the Columbia-Suicide Severity Rating Scale (C-SSRS) (
37). A toolkit from the National Institute of Mental Health for using the ASQ is available for free at
www.nimh.nih.gov/ASQ.
Clinical Assessment of Suicide Risk
A clinical assessment of suicide risk begins with detecting and characterizing suicidal thoughts. Questions can be drawn from the ASQ or the C-SSRS, or they can be paraphrased to inquire about whether an individual has had recent wishes to be dead and thoughts of killing oneself. Further assessment involves determining the frequency and duration of suicidal thoughts, the presence of a plan (and specificity of the plan), and the intensity of that plan (including the intent to act on a plan and perceived ease to avoid acting on thoughts).
Beyond suicidal thoughts, risk factors as described earlier are assessed, including past history of suicidal behavior and nonsuicidal self-injurious behavior, presence of psychiatric disorders, substance use, family history of suicide and psychiatric disorders, a history of trauma, and acute stressors. Access to lethal means of suicide is part of the assessment, and the presence of firearms in the home should always be determined as part of a suicide risk assessment. Connectedness is an important dimension of suicide risk in youths, and signs and symptoms of struggling in youths that deserve further assessment include pulling back from extracurricular activities, isolating in one’s room or otherwise withdrawing from family and social interactions, and declining grades.
Because suicidal thoughts may precede suicide attempts and death by suicide in some individuals, it is important to identify individuals who are experiencing them. However, in terms of risk of death by suicide, suicidal thoughts themselves exist on a continuum, on which the risk is much higher when there is detailed planning and intent to carry out a suicide plan. One way to conceptualize this continuum is depicted in
Figure 1.
The continuum proceeds from the left, corresponding to minimal risk of suicide, to the right, corresponding to extremely high and imminent risk. This helps explain why assessment of risk in individuals having suicidal thoughts includes asking about methods considered and the degree of detail. A nearly universal experience, not particularly associated with risk of suicide, is a wish to escape problems or stressors. Slightly further along the continuum is the experience of feeling so overwhelmed (by emotions or stressors) that the individual feels that death might be advantageous. This line of thought, without thoughts of actually taking action to end one’s own life, is sometimes called “passive” suicidal ideation. Next on the continuum is having thoughts about suicide without having seriously considered any methods to do it. Progressing along the continuum, individuals may have considered a plan to varying degrees of specificity. At some point, the individual may have considered the plan in enough detail to be prepared to carry it out (e.g., a plan of how and when to access a firearm to attempt suicide or to access the pills needed for a lethal ingestion). At the extreme end of the continuum, a patient might have a detailed plan with the intent to carry it out; these individuals are on the cusp of attempting suicide unless prevented from doing so.
Normally, movement along the continuum is expected to be gradual, giving opportunities for the patient to reach out for help and to utilize coping skills or take advantage of protective factors before they are on the extreme right side of the continuum. However, there are some factors that appear to make individuals at a higher risk for moving quickly to the extreme right side of the continuum. These “fast-track” factors include impulsivity from substance use, bipolar disorder, ADHD, or traumatic brain injury; a significant history of trauma; and young age (preadolescence) or intellectual disability (
Figure 2).
Prevention of Suicide
Detection of suicide risk necessitates steps to prevent it. Treatment of co-occurring psychiatric disorders such as mood, anxiety, and eating and substance use disorders, and ensuring connection with mental health treatment and longitudinal follow-up, can help reduce risk.
A structured approach to crisis planning, called the safety planning intervention (SPI), results in a written and prioritized list of strategies to cope and sources of support for patients to use in a suicidal crisis (
40). The six basic components of the SPI involve an understanding of the warning signs of a suicidal crisis; internal coping strategies that can be used; people and social settings that provide distraction; people (with name and contact information) whom the individual can ask for help; professionals, agencies, and hotlines that can be contacted in a crisis; and how the environment can be made safe (restriction of access to lethal means).
When the SPI is unable to provide a sufficient level of safety, a higher level of care and other interventions directly targeted at increasing safety may be necessary. This can include inpatient and partial hospitalizations, intensive outpatient treatment, and sometimes treatments specific to suicidal thoughts and behaviors.
Because connectedness and healthy relationships with family members and peers are protective against suicide, helping facilitate healthy engagement with activities and individuals is important, through both identifying existing possibilities with the SPI and improving these and fostering new ones through work with youths, their families, and their schools during longitudinal follow-up care.
Conclusions
With increasing rates of suicide in youths, making an impact relies on understanding key risk and protective factors. Identifying those at risk, assessing the acuity of this risk, and utilizing interventions to mitigate it are important skills for clinicians involved in youth mental health to prevent suicide.