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  • The act of intentionally and voluntarily causing one's own death
  • Warning signs of suicidal urges include self-isolation, saying goodbye and giving away possessions
  • Treatment may include addressing underlying causes, such as depression
  • Involves psychiatry, emergency medicine



Every day in our country, as many as 129 people take their own lives. Though it can be hard to understand suicide from a distance, suicide is the tenth leading cause of death in the U.S. Because so many people who die by suicide experience mental illness, better mental health treatment is one key to preventing suicide. 

Generally speaking, there are two types of suicide. A spontaneous suicide happens when a person responds to a highly emotional event, such as a marital breakup, perhaps under the influence of a substance such as alcohol. By contrast, a planned suicide is carried out after much deliberation. 

“Though it’s not uncommon in someone suffering from depression, it’s very concerning when a patient is having suicidal thoughts,” says Gerard Sanacora, MD, PhD, director of the Yale Depression Research Program.

What are the risk factors for suicide?

  • Mental Illness. An estimated 90 percent of people who attempt suicide are believed to have a treatable mental illness, at least in Western countries like the United States. Depression is the most common of those. Anxiety, substance abuse, and psychosis are also related to suicide. A history of suicide attempts is an important risk factor, as is a family history of suicide or suicide attempts. People who have attempted suicide once previously have between a 20 and 40 times increased risk of death from suicide compared to the general population. The increased risk is highest within the first year of an attempt.
  • Stress. Stressful life events are risk factors, especially ones that can cause humiliation, such as job loss. Divorce or the loss of a spouse can also be triggers. Having a chronic medical condition – such as AIDS, cancer or neurological disorder – is also a risk factor for suicide.
  • Prolonged stressors. Bullying, harassment and relationship problems can put teenagers at particular high risk. Teenagers are also more likely than older people to be influenced by another person’s suicide, and to take their life, too. 
  • Sex. Men die by suicide about four times as often as women, although women attempt suicide more often than men. 
  • Access. One of the most important risk factors is access to lethal means, such as a firearm in the home or a stockpile of medications.

How common are suicidal thoughts and suicide attempts?

There is  no complete up-to-date count of suicide attempts in the United States, but Centers for Disease Control & Prevention combines some data from hospitals with survey data.One survey from 2017 counting adults alone showed approximately 1.4 million attempted suicides.

How can a clinician detect suicidal tendencies?

“Clinicians need to get corroborative information from family members, to see if patients are exhibiting signs, especially after the recent loss of employment or of a relationship," Dr. Sanacora says. 

Warning signs of possible suicidal urges include a drastic change in a person’s appearance, a previous history of suicide attempts, substance abuse, a growing tendency to isolate himself and withdraw from activities, and evidence that the person is saying goodbye to others or giving away possessions.

As soon as someone is suspected to have suicidal thoughts, it’s important to get him or her to a health care provider immediately – even if that means an emergency room visit. “When we know someone is suicidal, we begin treating the underlying cause or illness, such as depression,” Dr. Sanacora says. “We also urge friends and family to remove any access to lethal weapons or drugs.”

What makes Yale Medicine’s approach to the prevention of suicide unique?

“Because it’s seen as risky, most drug development researchers avoid enrolling patients with suicidal thoughts into trials,” Dr. Sanacora says. For those with severe depression who haven’t responded to common therapies – a group at high risk of suicide – Yale Interventional Psychiatry Service offers experimental treatments. These include the drug ketamine, an anesthetic that quickly alleviates depression, and electroconvulsive therapy (ECT), a procedure in which small electrical currents are passed through the brain, relieving symptoms of depression.