- Clinical science
Suicide refers to the act of intentionally ending one's own life. If that action fails, it is called a suicide attempt. Suicide and suicide attempts are more broadly considered suicidal behavior. By definition, suicidal behavior requires both general thoughts about suicide and concrete, deliberate plans to act upon those ideas (suicidal ideation). While suicidal ideation can precede suicide and, therefore, should be investigated thoroughly, it often occurs independently of any suicidal behavior. While attempted suicide is more common in women, completed suicide is significantly more common in men. Suicidal ideation is often associated with psychiatric illness (e.g., major depressive disorder, bipolar disorder). The most important diagnostic step is the evaluation of possible suicidal ideation and prior suicide attempts. Acute management is focused on stabilization and preventing imminent acts of suicide (e.g., by admitting the patient to a psychiatric institution). After there is no longer an immediate risk of self-harm, underlying conditions and risk factors must be addressed (e.g., with treatment with antidepressants). Frequent follow-ups beginning soon after initial treatment are vital for preventing the recurrence of suicidal behavior.
- Suicidal behavior: includes suicide attempts and completed suicide
- Any thoughts of or plans to intentionally end one's own life that do not include preparatory behavior
- Suicidal ideation and behavior are often present simultaneously. 
- There are ∼ 47,000 suicides every year in the US.
- Suicide is the 10th leading cause of death for all ages and the 2nd leading cause in individuals 15–34 years of age.
- Sex: ♂ > ♀ 
- Method: > 50% of suicides are by firearm. 
- Incidence 
- Age: Peak incidence is 15–19 years. 
- Sex: ♀ > ♂ 
Completed suicides are more common in men, while suicide attempts are more common in women. 
Epidemiological data refers to the US, unless otherwise specified.
Risk factors for suicidal behavior 
- Previous suicide attempt (most important risk factor)
- Psychiatric disorders
- Recent psychiatric hospitalization
- History of aggressive behavior
- Other chronic and/or serious diseases (e.g., cancer or chronic pain)
- Age > 45 years
- Male sex:↑ risk of completed suicide
- Family member that died by suicide
- Social factors: unemployment, no spouse, poor social support/few social contacts, early loss of a parent
- Access to and/or possession of firearms: ↑ risk of completed suicide
- Socioeconomic status (refugees, homeless persons)
- History of sexual assault
SAD PERSONS are at risk for suicide: Sex (male), Age (> 45 years), Depression, Previous suicide attempt, Ethanol/substance use, Rational thinking loss (psychosis), Sick (chronic disease), Organized plan (acquisition of weapons/tools), No spouse or social support, Stated intent.
General psychiatric evaluation 
Ask specifically and directly about suicidal ideation and concrete intent/plans.
- Helps evaluate the imminent risk of suicide (i.e., need for hospitalization)
- Allows for assessment of whether the patient is in a position to act on their plans (e.g., possession of firearms)
- Investigate potential underlying conditions (e.g., mood disorders, schizophrenia, substance abuse, recent severe psychological stress/trauma).
- Ask about previous suicide attempts (also within the family), feelings of despair, and ambivalence towards death.
- If previously depressed and agitated patients suddenly become calm or less symptomatic, the risk of suicidal behavior increases.
- 5-Hydroxyindoleacetic acid (5-HIAA): low 5-HIAA in CSF correlate with suicide attempts in patients with mood disorders (especially following prior suicide attempts) 
Sudden improvement of symptoms in depressed patients (e.g., a normally agitated patient who is calm) may indicate an imminent suicide plan.
If there is any reason to suspect suicidal ideation, ask the patient about it!
Acute management 
Imminent risk of suicidal behavior 
The risk of suicide is imminent if suicidal ideation, intent, and a concrete plan are present.
- Goal: : risk reduction by actively preventing the patient from suicidal behavior and assuring the patient's safety
Hospitalization: preferably admission to a psychiatric unit
- Ideally, the patient is admitted to the hospital voluntarily.
- Against the patient's will if the patient is uncooperative and in immediate danger of self-harm
- Remove hazardous objects from the patient's environment that could be used in a suicide attempt (e.g., remove firearms from home).
- Do not leave the patient alone or even with his or her family.
- If necessary, involve the authorities (e.g., local police).
- Hospitalization: preferably admission to a psychiatric unit
- Special patient group: If minors are hospitalized due to an imminent risk of suicidal behavior, their parents must be informed; however, parental (or legal guardian) consent for such action is not required.
Elevated risk of suicidal behavior
- Involve the family of the patient and inquire about the patient's psychological and social situation (e.g., history of suicidal ideation, access to firearms, social connections).
- Take measures to increase the patient's social contacts and interaction with medical professionals.
- Treatment of underlying psychiatric disorders
- Pharmacological therapy
- Mood stabilizers: Lithium is an effective mood stabilizer in suicidal patients with . 
- SSRIs; (and other antidepressants): can initially cause increased activity, which may lead to increased suicidal behavior; in adolescents, especially within the first few weeks of treatment 
- Tricyclic antidepressants, MAO-inhibitors, venlafaxine: Avoid if possible, since lethal overdoses can occur relatively easily with these medications.
- Electroconvulsive therapy: used for major depressive disorder and bipolar disorder that does not respond to other treatments
- Pharmacological therapy
- Counseling on improvement of social circumstances that constitute risk factors for suicidal behavior (e.g., changing living conditions and increasing social contacts).
If antidepressants such as SSRIs are given, the increase in energy and motivation occurs sooner than the improvement in mood. Therefore, suicide risk may increase during the first weeks of treatment. Close observation and frequent follow-ups are vital!
If there is any evidence of suicidal ideation, all firearms should be removed from the patient's home!
Any patient with the intent to act on a concrete suicide plan should be hospitalized immediately!
- Risk of suicide is generally increased in the following settings:
- After previous suicide attempt(s)
- During the first weeks following discharge from psychiatric care
- During recovery from severe depression
- To prevent suicide, regular follow-ups should occur:
- Soon after discharge (ideally within 7 days) 
- Frequently (vital for long-term outcome)