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Suicidal Behavior


Paula J. Clayton

, MD, University of Minnesota School of Medicine

Last full review/revision Oct 2019| Content last modified Oct 2019
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Suicidal behavior includes completed suicide and attempted suicide. Thoughts and plans about suicide are called suicide ideation.

  • Suicide usually results from the interaction of many factors, usually including depression.

  • Some methods, such as guns, are more likely to result in death, but choice of a less lethal method does not necessarily mean that the intent was less serious.

  • Any suicide threat or suicide attempt must be taken seriously, and help and support should be provided.

  • A telephone hotline is available for people who are considering suicide.

Suicidal behavior includes the following:

  • Completed suicide: An intentional act of self-harm that results in death.

  • Attempted suicide: An act of self-harm that is intended to result in death but does not. A suicide attempt may or may not result in injury.

Nonsuicidal self-injury is an act of self-harm that is not intended to result in death. Such acts include inflicting scratches on the arms, burning oneself with a cigarette, and overdosing on vitamins. Nonsuicidal self-injury may be a way to reduce tension or may be a plea for help from people who still wish to live. These acts should not be dismissed lightly.

Information about the frequency of suicide comes mainly from death certificates and inquest reports and probably underestimates the true rate. Even so, suicidal behavior is an all-too-common health problem. Suicidal behavior occurs in men and women of all ages, races, creeds, incomes, educational levels, and sexual orientations. There is no typical suicide profile.

Completed suicide worldwide

Worldwide, almost 800,000 people die by suicide every year.

Suicide was the second leading cause of death among people aged 15 to 29 years.

Evidence suggests that for each person who dies by suicide, there are many more people who attempt suicide. This ratio varies widely by country, region, sex, age, and method.

Completed suicide in the United States

In the United States, there were almost 47,000 completed suicides in 2017. On average, there are about 129 suicides each day.

In 2016, the suicide rate was

  • Highest in people aged 45 to 64

  • 2nd highest in people aged 85 and over

As a leading cause of death, suicide ranks 10th overall. Among younger people, suicide ranks as follows:

  • 2nd among people aged 10 to 34

  • 4th among those aged 35 to 54

  • 8th among those aged 55 to 64

In all age groups, men who commit suicide outnumber women almost 4 to 1. The reasons are unclear, but the following may be involved:

  • When men have problems, they are less likely to seek help—from friends and/or health care practitioners.

  • Alcohol abuse and substance use disorders, which appear to contribute to suicidal behavior, are more common among men.

  • Men are more aggressive and use more lethal means when they attempt suicide.

  • The number of suicides in men includes suicides in the military and among veterans. Both groups have a higher proportion of men to women.

In 2016, the suicide rate was highest among American Indians and Alaska Natives and the second highest among non-Hispanic whites.

Did You Know?

  • Suicide is a leading cause of death among young people, but the rate of completed suicides is highest in people aged 45 to 64 and second highest in people aged 85 and over.

  • Men are more likely to commit suicide than women.

  • For every person who commits suicide, there are many more who attempt it.

Attempted suicide in the United States

Each year in the United States, over 1 million people attempt suicide. There are about 25 attempts for every completed suicide. Many people make repeated attempts. However, only 5 to 10% of people who make an attempt eventually die by suicide. Attempted suicide is particularly common among adolescent girls. Girls aged 15 to 19 make 100 suicide attempts for every suicide completed, and they attempt suicide 100 times more often than boys. Across all age groups, women attempt suicide 2 or 3 times as often as men, but men are 4 times more likely to die in their attempts. Older people attempt suicide 4 times for every completed suicide.

In people who attempt suicide, life expectancy is significantly reduced. Much of the decrease in life expectancy seems to result from physical disorders rather than later, completed suicide.

Causes of Suicidal Behavior

About one in six people who kill themselves leaves a suicide note, which sometimes provides clues as to why.

Suicidal behaviors usually result from the interaction of several factors.

The most common factor that contributes to suicidal behavior is

Depression, including the depression that is part of bipolar disorder, is involved in over 50% of attempted suicides and an even higher percentage of completed suicides. Depression can occur out of the blue, be triggered by a recent loss or other distressing event, or result from a combination of factors. In people with depression, marital problems, recent arrest or trouble with the law, unhappy or ended love affairs, disputes with parents or bullying (among adolescents), or the recent loss of a loved one (particularly among older people) may trigger a suicide attempt. The risk of suicide is higher if people with depression also have significant anxiety.

People with certain medical disorders may become depressed and attempt or complete suicide. Most disorders associated with increased suicide rates either directly affect the nervous system and brain (as occurs in AIDS, multiple sclerosis, temporal lobe epilepsy, head injuries) or involve treatments that can cause depression (such as certain drugs used to treat high blood pressure).

In older people, about 20% of suicides may at least partly be a response to serious chronic and painful physical disorders.

Traumatic childhood experiences, including physical and sexual abuse, increase the risk of attempted suicides, perhaps because depression is common among people who have had such experiences.

Use of alcohol may intensify depression, which, in turn, makes suicidal behavior more likely. Alcohol also reduces self-control. About 30% of people who attempt suicide drink alcohol before the attempt, and about half of them are intoxicated at the time. Because alcoholism, particularly binge drinking, often causes deep feelings of remorse during dry periods, alcoholics are suicide-prone even when sober.

Almost all other mental disorders also put people at risk of suicide.

People with schizophrenia or other psychotic disorders may have delusions (fixed false beliefs) that they find impossible to cope with, or they may hear voices (auditory hallucinations) commanding them to kill themselves. Also, people with schizophrenia are prone to depression.

People with borderline personality disorder or antisocial personality disorder, especially those with a history of violent behavior, are also at higher risk of suicide. People with these disorders tolerate frustration poorly and react to stress impetuously, sometimes leading to self-harm or aggressive behavior.

Living alone increases the risk of suicidal behavior. People who have been separated, divorced, or widowed are more likely to complete suicide. Suicide is less common among people who are in a secure relationship than among single people.


Risk Factors for Suicidal Behavior

  • American Indian or Alaska Native

  • Male

  • Painful or disabling illness

  • Living alone

  • Economic downturns or debt

  • Unemployment

  • Bereavement or loss

  • Humiliation or disgrace

  • Hopelessness

  • Aggressive or impulsive behavior

  • Depression, especially when it is accompanied by anxiety or is part of bipolar disorder

  • Recent hospitalization for depression

  • Most other mental disorders, such as personality disorders

  • Persistent sadness even when other symptoms of depression are lessening

  • A history of drug or alcohol abuse

  • A history of prior suicide attempts

  • A history of suicide or mental disorders in family members

  • Traumatic childhood experiences, including physical or sexual abuse

  • Preoccupation with and talk about suicide

  • Well-defined plans for suicide

Antidepressants and the risk of suicide

The risk of suicide attempts is greatest in the month before starting antidepressant treatment, and the risk of death by suicide is no higher after antidepressants are started. However, antidepressants slightly increase the frequency of suicidal thoughts and attempts (but not of completed suicide) in children, adolescents, and young people. So parents of children and adolescents should be warned, and children and adolescents should be carefully monitored for side effects such as increased anxiety, agitation, restlessness, irritability, anger, or a shift into hypomania (when people feel full of energy and cheerful but are often easily irritated, distracted, and agitated), especially during the first few weeks after they start taking the drug.

Because of public health warnings about the possible association between taking antidepressants and an increased risk of suicide, doctors started prescribing antidepressants more than 30% less often for children and young people. However, during this same time, suicide rates among young people temporarily increased by 14%. Thus, it is possible that by discouraging drug treatment of depression, these warnings resulted in more, not fewer, deaths by suicide.

When people with depression are given antidepressants, doctors take certain precautions to reduce the risk of suicidal behavior:

  • Giving people antidepressants in amounts that would not cause death

  • Scheduling more frequent visits when treatment is first started

  • Clearly warning people and their family members and significant others to be alert for worsening symptoms or suicidal ideation

  • Instructing people and their family members and significant others to immediately call the doctor who prescribed the antidepressant or to seek care elsewhere if symptoms worsen or suicidal thoughts occur

Did You Know?

  • Taking antidepressants has been linked with an increased risk of suicidal thoughts and attempts, but not taking antidepressants may increase the risk of suicide much more.

  • Although most men and women who kill themselves use guns, more than twice as many men complete suicide this way.


The choice of method is often influenced by cultural factors and availability of the means to commit suicide (for example, a gun). It may or may not reflect the seriousness of intent. Some methods (such as jumping from a tall building) make survival virtually impossible, whereas other methods (such as overdosing on drugs) make rescue possible. However, even if a person uses a method that proves not to be fatal, the intent may have been just as serious as that of a person whose method was fatal.

Suicide attempts most often involve drug overdose and self-poisoning. Violent methods, such as shooting and hanging, are uncommon among suicide attempts because they usually result in death.

Most completed suicides involve guns. In the United States, guns are used in about 50% of suicides. Men use this method more than women. Other methods include hanging, poisoning, jumping from a height, and cutting. Some methods, such as driving off a cliff, can endanger others.

Worldwide, poisoning with pesticides accounts for about 30% of completed suicides.

Prevention of Suicidal Behavior

Although some attempted or completed suicides come as a shock even to family members and friends, many people give clear warnings. Any suicide threat or suicide attempt must be taken seriously. If it is ignored, a life may be lost.

If a person is imminently threatening or has already attempted suicide, the police should be contacted immediately so that emergency services can arrive as soon as possible. Until help arrives, the person should be spoken to in a calm, supportive manner.

A doctor may hospitalize people who have threatened or attempted suicide. Most states allow a doctor to hospitalize people against their wishes if the doctor believes that they are at high risk of harming themselves or other people.


Suicide Intervention: National Suicide Prevention Lifeline

People threatening suicide are in crisis. The National Suicide Prevention Lifeline (1-800-273-TALK) provides crisis intervention for such people throughout the United States. Suicide prevention centers are staffed by specially trained volunteers.

When potentially suicidal people call the hotline, a volunteer does the following:

  • Seeks to establish a relationship with them, reminding them of their identity (for example, by using their name repeatedly)

  • May offer constructive help for the problem that brought on the crisis and encourage them to take positive action to resolve it

  • May try to facilitate emergency face-to-face professional help for them

Sometimes people call a hotline to say that they have already committed a suicidal act (for example, taken a drug overdose or turned on the gas) or are in the process of doing so. In such cases, the volunteer tries to obtain their address. If that is not possible, another volunteer contacts the police to trace the call and attempt a rescue. If possible, people are kept talking on the telephone until the police arrive.


Doctors take any suicidal act seriously, regardless of whether the person actually intended to commit suicide or not.

If people seriously injure themselves, doctors evaluate and treat the injury and typically admit the person to the hospital. If people have taken an overdose of a potentially lethal drug, doctors immediately take steps to prevent absorption of the drug and speed its elimination from the body. People are also given any available antidote and provided with supportive care, such as a breathing tube.

After the initial evaluation, people who have attempted suicide are referred to a psychiatrist, who tries to identify problems that contributed to the attempt and plan appropriate treatment.

To identify problems, psychiatrists do the following:

  • Listen to what the person has to say

  • Try to understand what made the person attempt suicide, what led up to the attempt, and where and how it occurred

  • Ask about symptoms of mental disorders that increase the risk of suicidal behavior

  • Ask whether the person is being treated for a mental disorder, including whether the person is taking any drugs to treat it

  • Evaluate the person's mental state, looking for signs of depression, anxiety, agitation, panic attacks, severe insomnia, other mental disorders, and alcohol or substance use and abuse

  • Ask about personal and family relationships as well as social networks, because they are often relevant to the suicide attempt and the follow-up treatment

  • Talk to close family members and friends, and ask them about the person's use of alcohol, marijuana, pain relievers, and drugs of abuse

  • Help the person identify things that trigger thoughts of suicide and help the person plan ways to deal with the triggers

Because depression increases the risk of suicidal behavior, doctors carefully monitor people with depression for suicidal behavior and thoughts.

Some evidence suggests that using lithium, antidepressants, and antipsychotics to treat mood disorders in people who are at risk of suicide may reduce the number of completed suicides. Treating schizophrenia with clozapine reduces the risk of suicide.

Impact of Suicidal Behavior

Death by suicide has a marked emotional effect on all involved. Family, friends, and doctors may feel guilt, shame, and remorse at not having prevented the suicide. They may also feel anger toward the person. Eventually, they may realize that they could not have prevented the suicide.

Sometimes a grief counselor or a self-help group can help family and friends deal with their feelings of guilt and sorrow. The primary care doctor or local mental health services (for example, at the county or state level) can often help locate these resources. In addition, national organizations, such as the American Foundation for Suicide Prevention, maintain directories of local support groups. Resources are also available on the Internet.

The effect of attempted suicide is similar. However, family members and friends have the opportunity to resolve their feelings by responding appropriately to the person's cry for help.

Physician Aid in Dying (formerly, Assisted Suicide)

Physician aid in dying refers to the assistance given by physicians to people who wish to end their lives. It is very controversial because it reverses the doctor's usual goal, which is to preserve life. However, physician aid in dying is legal in 9 U.S. states (California, Colorado, Hawaii, Maine, Montana, New Jersey, Oregon, Vermont, and Washington) and the District of Columbia. Assisted suicide is also legal in Switzerland, Germany, and Canada. In the rest of the United States, doctors can provide treatment intended to minimize physical and emotional suffering, but they cannot intentionally hasten death.

Physician aid in dying is also legal in some other countries.

More Information about Suicidal Behavior

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