Suicide Risk Assessment

How to Cite This Chapter: van Reekum EA, Brasch J. Suicide Risk Assessment. McMaster Textbook of Internal Medicine. Kraków: Medycyna Praktyczna. Accessed July 23, 2024.
Last Updated: May 27, 2022
Last Reviewed: May 27, 2022
Chapter Information

Definition, Etiology, PathogenesisTop

Suicidal ideation is any thought about ending one’s life, from vague and fleeting to intense and detailed. Suicidal thoughts can be passive (desire for death with no plan or intent to cause death) or active (with a plan to die).

Self-harm behaviors are deliberate actions to harm oneself. They may include suicide attempts or behaviors not intended to cause death (eg, superficial cutting). While there may or may not be lethal intent, these behaviors can be dangerous, are a risk factor for suicide, and their presence should precipitate psychiatric assessment.

Thoughts of suicide, plans for suicide, and self-harm behaviors are common in the general population, with a lifetime prevalence of 9% for suicidal ideation. Despite this high prevalence, death by suicide is relatively rare. A person’s death by suicide has a lifelong and profound effect on their family, friends, and health-care team.

Suicide is an intentional end to one’s life. There are many proposed models to understand suicide (which is still poorly understood), most of which describe relationships between proximal or immediate factors on the background of distal, predisposing risks. Most models recognize an interaction between biological factors (eg, altered neurotransmission, inflammation), psychological factors (eg, impulsivity), and environmental factors (eg, sociocultural norms, inadequate health care). Suicidal patients often report associated hopelessness, perception of having unsolvable problems, and wanting to escape from distressing situations.

In 2020 there were 3839 confirmed suicides in Canada. At a rate of 10.1 per 100,000 people in 2020, this was the lowest suicide rate in >2 decades. This trend towards lowered suicide rates during the early coronavirus disease 2019 (COVID-19) pandemic was replicated in several other middle-income and high-income countries. The suicide rate for men was 3 times higher than the rate for women. The rate was highest in those aged 50 to 59 years. Overall, suicide was the 12th leading cause of death, and the second leading cause in young individuals aged 10 to 19 years. Suicide rates are consistently higher among some, but not all, Indigenous communities in Canada. In the Inuit community the rate was 72.3 per 100,000 person-years, compared with 8.0 in non-Indigenous populations. This is suggested to be due to the colonialism-related trauma and ongoing systemic racism, which can lead to a loss of control over land and living conditions, marginalization, and poor access to housing and health care, such as mental health resources.

Suicide risk factors (Table 1) are associated with an overall increased risk of suicide but do not reflect the immediacy of this risk. Psychiatric disorders (especially schizophrenia, mood and substance use disorders) are present in 90% of suicide deaths. The strongest predictor is history of nonfatal suicide attempt, with 4% of this population dying by suicide within 5 years of an attempt.

Clinical Features and AssessmentTop

Suicide and suicidal ideation are strongly associated with psychiatric disorders. However, patients hospitalized for nonpsychiatric reasons can also have thoughts of suicide. While there are no universally accepted guidelines on suicide management, some experts have suggested suicide screening for all medical and surgical inpatients given their heightened risk from physical disorders. At the very least, and based upon epidemiologic data and clinical expertise, we suggest screening for suicide if any of these are present:

1) There is a significant clinical change (eg, change in behavior or affect like new tearfulness or agitation, onset of delirium, or insomnia).

2) The patient recently received a life-altering medical diagnosis or prognosis.

3) The patient has recently experienced a major loss (eg, loss of independence, relationship, vocation, limb).

4) There are substantial psychosocial stressors (eg, interpersonal, financial).

5) Medical history includes psychiatric disorders (particularly schizophrenia, depressive, bipolar and substance use disorders) or self-harm behavior.

All physicians are capable of screening for suicide. Suicide screens are generally brief, supported by patients, and do not cause patients to act on suicidal thoughts. Exploring a patient’s thoughts of suicide does not increase the risk of an attempt and could abate suffering by allowing the patient to share distressing thoughts. Patients may be more likely to trust and share suicidal thoughts with clinicians who show empathy and listen nonjudgmentally.

We suggest including questions about mood and suicidal ideation during the review of systems if the topic has not yet been explored. It may be helpful to gently transition to suicide screening after discussing physical symptoms or mood. Initial screening questions could be any of the following:

1) “Do you ever have thoughts that life is not worth living?”

2) “Do you ever wish you could go to sleep and not wake up?”

3) “Do things ever get so bad that you wish you weren’t alive anymore?”

A positive response to any of these questions should be followed up with a more comprehensive assessment that includes inquiring about:

1) The nature of the thoughts (“What sorts of thoughts have you had?”).

2) The frequency and intensity of thoughts of suicide.

3) The motivation driving the thoughts, if any.

4) Specific plans and any actions taken to prepare for death.

5) Associated emotions, including sadness, anxiety, hopelessness, relief.

6) Past suicide attempts and other self-harm behaviors.

7) Protective factors (“What prevents you from acting on these thoughts?” Eg, children, pets, religion).

8) Risk factors for suicide (see Table 1).

9) Additionally, collateral information from family, friends, and health-care professionals involved in the patient’s care should be sought.

Patients that you identify as being at an elevated risk, especially those who have made a medically serious suicide attempt, should have a psychiatric evaluation prior to discharge from hospital.

Several screening or clinical evaluation tools are available (eg, the Columbia-Suicide Severity Rating Scale is used widely), but there is no evidence of benefit that would support the use of these tools. The use of a checklist could lead to false reassurance and make a comprehensive assessment less likely. Careful clinical interview, thoughtful assessment, and a reasonable level of clinician alertness are likely the best approach.

It is not possible to predict suicide. However, identifying suicidal ideation is important, as it is a marker of distress and severity of psychiatric disorders. Identifying suicidal ideation can lead to referrals to mental health care and guide treatment of underlying psychiatric disorders, and in these ways ease suffering in suicidal patients and reduce risk.


1. General considerations: Interventions depend on the evaluation of risk. Patients who have made a medically serious suicide attempt or disclose active suicidal ideation need prompt assessment by a mental health professional and a secure setting with no access to lethal means. In consultation with a psychiatrist, factors to consider that inform treatment include the severity of suicidal ideation, changes in the level of ideation or intent, risk factors, collateral information, and presence of psychiatric disorders.

There is a paucity of high-quality data supporting any single treatment for patients presenting with suicidal ideation, self-harm behavior, or both. Personalized interventions that target the individual’s suffering and unique modifiable risk factors are thus preferred, which may in turn mitigate suicide risk. Possible interventions include hospitalization for high-risk patients, and pharmacologic and non-pharmacologic approaches.

2. Hospitalization: A patient may need hospitalization due to elevated suicide risk. In these cases, there is typically acute psychiatric illness that may respond to inpatient treatment, so patients should be transferred to specialized mental health wards once medically cleared. These patients may require involuntary hospitalization, frequent observation, and physical or chemical restraints to prevent harm to themselves or others.

3. Pharmacotherapy: There is no specific treatment for suicidal ideation or self-harm behavior. Medication choices are guided by the underlying psychiatric illnesses.

For adults with moderate to severe depressive disorders, consider a selective serotonin reuptake inhibitor (SSRI) given the relatively low toxicity in overdose (prescribe limited amounts). Avoid tricyclic antidepressants due to a high risk of death if overdosed. While not empirically supported for suicide management specifically, we suggest treating substance use disorders with first-line medications (eg, naltrexone in alcohol use disorder), given the potential to reduce impulsivity and risk of suicide.

For patients with depressive or bipolar disorders, lithium prophylaxis has long been thought to reduce suicide risk due to positive findings from observational data. A pooled analysis of mainly small trials with short follow-up provided support for antisuicidal properties of lithium in this population, however, a recent trial yielded negative results. Due to the narrow therapeutic window and high risk of death in overdose, our pattern of practice is to consider lithium prophylaxis only for mood disorder in patients deemed at a high risk of suicide.Evidence 1Weak recommendation (benefits likely outweigh downsides, but the balance is close or uncertain; an alternative course of action may be better for some patients). Low Quality of Evidence (low confidence that we know true effects of the intervention). Quality of Evidence lowered due to imprecision, inconsistency, and publication bias. Lewitzka U, Severus E, Bauer R, Ritter P, Müller-Oerlinghausen B, Bauer M. The suicide prevention effect of lithium: more than 20 years of evidence-a narrative review. Int J Bipolar Disord. 2015 Dec;3(1):32. doi: 10.1186/s40345-015-0032-2. Epub 2015 Jul 18. PMID: 26183461; PMCID: PMC4504869. Cipriani A, Hawton K, Stockton S, Geddes JR. Lithium in the prevention of suicide in mood disorders: updated systematic review and meta-analysis. BMJ. 2013 Jun 27;346:f3646. doi: 10.1136/bmj.f3646. PMID: 23814104. Katz IR, Rogers MP, Lew R, et al; Li+ plus Investigators. Lithium Treatment in the Prevention of Repeat Suicide-Related Outcomes in Veterans With Major Depression or Bipolar Disorder: A Randomized Clinical Trial. JAMA Psychiatry. 2022 Jan 1;79(1):24-32. doi: 10.1001/jamapsychiatry.2021.3170. PMID: 34787653; PMCID: PMC8600458.

Patients with schizophrenia have high rates of suicide and there is low-certainty evidence that clozapine reduces suicide risk in this population. Due to the substantial harms of this medication, we suggest considering clozapine in patients with schizophrenia who are judged to be at a high risk of suicide.Evidence 2Weak recommendation (benefits likely outweigh downsides, but the balance is close or uncertain; an alternative course of action may be better for some patients). Low Quality of Evidence (moderate confidence that we know true effects of the intervention). Quality of Evidence lowered due to imprecision. Taipale H, Lähteenvuo M, Tanskanen A, Mittendorfer-Rutz E, Tiihonen J. Comparative Effectiveness of Antipsychotics for Risk of Attempted or Completed Suicide Among Persons With Schizophrenia. Schizophr Bull. 2021 Jan 23;47(1):23-30. doi: 10.1093/schbul/sbaa111. PMID: 33428766; PMCID: PMC7824993. Meltzer HY, Alphs L, Green AI, et al; International Suicide Prevention Trial Study Group. Clozapine treatment for suicidality in schizophrenia: International Suicide Prevention Trial (InterSePT). Arch Gen Psychiatry. 2003 Jan;60(1):82-91. doi: 10.1001/archpsyc.60.1.82. Erratum in: Arch Gen Psychiatry.2003 Jul;60(7):735. PMID: 12511175.

Lithium and clozapine should be started and initially managed by psychiatrists, as each requires careful consideration of indications, monitoring, has significant adverse effects, and is toxic in overdose.

There is recent interest in ketamine and esketamine to manage suicidal thoughts, however, long-term efficacy, safety, and effect on suicide risk are unknown. Emerging data suggest that esketamine may even worsen suicidal thoughts. No recommendation can be provided at present.

4. Nonpharmacologic approaches: Several nonpharmacologic interventions may reduce suicide, self-harm behaviors, and frequency of suicidal ideation. However, the available evidence is generally of low quality and there is uncertainty in the literature to support any single approach. Interventions with empirical support are typically structured therapies delivered in individual or group settings. The resources may not be available in all communities, although the growing availability of online therapy is increasing access.

Structured cognitive behavioral therapy (CBT) and dialectical behavior therapy (DBT) may reduce the frequency of repeated self-harm behaviors. Evidence supports the use of brief suicide prevention interventions (eg, scheduled phone calls) in reducing suicide attempts in patients at a high risk of suicide. There is strong evidence of benefit for family-based interventions for adolescents with suicidality.

5. Electroconvulsive therapy (ECT): While in specialized settings, patients at very high risk of suicide should be considered for ECT.


Suicide prevention is a public health issue with initiatives that can be targeted at individual, health-care system, community, and societal levels. Presently there is no single approach that is preferred, and ideally prevention efforts will include many of the following:

1. Secure hospital environment: Mental health units designed to reduce hanging risk may prevent some suicide deaths. Frequent or constant observation and minimizing access to lethal means may enhance safety for the suicidal patient (eg, not storing sharps and medical equipment in the patient’s room, removing cords and bags). Many hospitals have implemented suicide prevention measures including staff training, patient care protocols, and environmental reviews to minimize risks. Zero Suicide ( is a comprehensive hospital-based quality improvement initiative that offers a framework to providing suicide-safer care.

2. Means restriction: Reducing access to lethal means is a harm reduction strategy at multiple levels. Suicidal patients and their family should be asked about access to firearms, lethal medications, and other materials for suicide methods they are considering. At the community level, evidence supports approaches that reduce access to lethal means (eg, barriers at jumping sites).

3. Crisis support: A growing number of communities have access to crisis supports, including telephone crisis lines, drop-in mental health centers, and outreach teams that assess people in their home or other community setting. Patients with suicidal thoughts may benefit, at least over the short term, from a safety plan that describes actions, contacts, and strategies to cope should they develop active suicidal ideation.

4. Education and access to care: Enhanced training for family physicians that supports their assessment and treatment of psychiatric disorders is effective for reducing suicide risk at the population level. Similarly, access to mental health care is associated with fewer suicides. Educational initiatives and stigma reduction programs can reduce suicide rates in youth populations.

Suicide of any hospitalized patient is an uncommon but tragic event. These are critical incidents and should be explored in a death review that examines circumstances of the death and seeks to prevent similar deaths but does not find fault or assign blame. Health-care providers who lose a patient to suicide should be offered supportive counseling. Postevent support to family and friends following a suicide loss may reduce the development of pathology in the bereaved.


Table 16.19-1. Risk factors for suicide

Epidemiologic and societal

– Inadequate access to health carea

– Male gender

– Age 45 to 59 years (in Canada)

– Sexual identity (LGBTQ2S+ community)

– Some Indigenous populations (Inuit, First Nations youth in Canada)


– Personality factors (impulsivity, pessimism)a

– Family history of suicide and genetic loading

– Early traumatic life events

– Cognitive deficits


– Psychiatric disorder (mood and substance use disorders, schizophrenia)a

– Psychosocial crisis (major life events, stressors, losses)a

– Feelings of hopelessness and social isolationa

– Physical disordera 

– Access to meansa

– Prior suicide attempt and/or self-harm behaviorb

– Local epidemics of suicide and media portrayals

a May be modifiable.

b Strongest risk factor.

Adapted from Hawton K, van Heeringen K (2009), Turecki et al. (2019), and Statistics Canada (2017).

We would love to hear from you

Comments, mistakes, suggestions?

We use cookies to ensure you get the best browsing experience on our website. Refer to our Cookies Information and Privacy Policy for more details.