Suicide and

Suicidal Behavior

Matthew K. Nock, Guilherme Borges, Evelyn J. Bromet, Christine B. Cha, Ronald C. Kessler, and Sing Lee

Epidemiol Rev. 2008 ; 30(1): 133–154. doi:10.1093/epirev/mxn002.

Introduction An updated review of the epidemiology of suicide and

suicidal behavior. Extend earlier reviews in this area in two important ways:

Provide an update on the prevalence of suicidal behavior over the past decade.

Review data from multiple countries, on all age groups, and on different forms of suicidal behavior, providing a comprehensive picture of the epidemiology of suicidal behavior.

Outline of the articleIn this review, the authors First, review data on the current rates of and recent tr

ends in suicide and suicidal behavior in the United States and cross-nationally.

Next, review data on the onset, course, and risk and protective factors for suicide and suicidal behavior.

Finally, summarize data from recent suicide prevention efforts and conclude with suggestions for future research.

Terminology and definitions in suicide research

Suicide: the act of intentionally ending one's own life. Nonfatal suicidal thoughts and behaviors:

suicide ideation: thoughts of engaging in behavior intended to end one's life

suicide plan: the formulation of a specific method through which one intends to die

suicide attempt: engagement in potentially self-injurious behavior in which there is at least some intent to die.

Nonsuicidal self-injury : self-injury in which a person has no intent to die (not the focus of this review)

Materials and Methods

Main data sources Suicide:

The National Vital Statistics System of the Centers for Disease Control and Prevention (CDC)

WHO Suicidal behavior:

CDC (the National Electronic Injury Surveillance System) US National Library of Medicine's PubMed electronic

database

Results Suicide in the United States

Current rates Recent trends Cross-national suicide rates

Current rates Recent trends Suicidal behavior in the United States

Current rates Recent trends Onset and course Suicidal behavior cross-nationally

Current rates Recent trends Onset and course Risk factors Protective factors Prevention/intervention programs

1. Suicide in the United States Current rates

In the United States, suicide occurs among

10.8 per 100,000 persons, is the 11th-leading cause of death, and accounts for 1.4 percent of all US deaths.

A more detailed examination of the data by sex, age, and race reveals significant sociodemographic variation in the suicide rate.

Numbers of suicide deaths in the United Statesby race, sex, and age group, 2005.

1. Suicide in the United States-Recent trendsNumbers of suicide deaths in the United States

by sex, age group, and year, 1990–2005.

2. Cross-national suicide rates Current rates

International data from the WHO indicate that suicide

occurs in approximately 16.7 per 100,000 persons per

year

The 14th-leading cause of death worldwide

Accounts for 1.5 percent of all deaths.

Numbers of suicide deaths in numerous nations for the most recent year available

Eastern Europe

Central and South America

United States, Western Europe, Asia

1.3:1

0.9:12.0:1

3.1-7.5:1

2. Cross-national suicide rates Recent trends

Definitive data do not exist on worldwide trends in suicide mortality because of cross-national differences in reporting procedures and data availability.

Nevertheless, the data maintained by the WHO suggest that: the global rate of suicide increased between 1950 and 2004,

especially for men. the number of self-inflicted deaths will increase by as much as

50 percent from 2002 to 2030.

3. Suicidal behavior in the US -Current ratesRates of nonfatal self-injury in the US

by sex and age group, 2006 (CDC)

3. Suicidal behavior in the US -Current rates (paper)

Adults

(ages ≥18 years)

Adolescents

(ages 12–17 years)

Suicide Ideation

Lifetime prevalence 5.6–14.3 % 19.8–24.0%

Twelve-month prevalence

2.1–10.0% 15.0–29.0%

Suicide Plans

Lifetime prevalence 3.9%

Twelve-month prevalence

0.7–7.0% 12.6–19.0%

Suicide Attempts

Lifetime prevalence 1.9–8.7% 3.1–8.8%

Twelve-month prevalence

0.2–2.0% 7.3–10.6%

Adults have a lower lifetime prevalence than adolescents?• One possible explanation is the rates of suicidal behavior in the US are increasing dramatically among adolescents, but this is inconsistent with data on trends in adolescent suicide and suicidal behaviors. • A more likely explanation is that adults underreport lifetime suicidal behaviors.

3. Suicidal behavior in the US –Recent trendsRates of nonfatal self-injury in the United States

by age group, and year, 2001–2006(CDC)

3. Suicidal behavior in the US –Recent trends CDC data shows the rate of nonfatal self-injury (both suicidal and

nonsuicidal in nature) increased during this period. Data from systematic review: Data on the 12-month prevalence of suicidal behaviors among

adults has remained stable in recent years. In the decade between 1990–1992 and 2001–2003, the 12-month prevalence

did not change significantly for suicide ideation (2.8%→3.3%), suicide plans

(0.7%→1.0%), or suicide attempts (0.4%→0.6%).

Data on the 12-month prevalence of suicidal behaviors among

adolescents has decreased. From 1991 to 2005 there was a decrease in the rates of suicide ideation

(29.0%→16.9%) and plans (18.6%→13.0%) but no such decrease for

attempts (7.3%→8.4%).

3. Suicidal behavior in the US –Onset and course

Onset The most consistently reported pattern is that the risk of

first onset for suicidal behavior increases significantly at the start of adolescence (12 years), peaks at age 16 years, and remains elevated into the early 20s.

This means that adolescence and early adulthood are the times of greatest risk for first onset of suicidal behavior.

Early stressors such as parental absence and family history of suicidal behavior have been associated with an earlier age of onset.

3. Suicidal behavior in the US –Onset and course

Course (few researches) 34% of lifetime suicide ideators go on to make a suicide plan 72% of persons with a suicide plan go on to make a suicide

attempt 26% of ideators without a plan make an unplanned attempt Majority of these transitions occur within the first year after

onset of suicide ideation (60% for planned first attempts and 90% for unplanned first attempts).

4. Suicidal behavior cross-nationally Current rates

Adults

(ages ≥18 years)

Adolescents

(ages 12–17 years)

Suicide Ideation

Lifetime prevalence 3.1–56.0 % 21.7–37.9 %

Twelve-month prevalence

1.8–21.3 % 11.7–26.0 %

Suicide Plans

Lifetime prevalence 0.9–19.5 % 3.0 %

Twelve-month prevalence

0.5–12.2 % 5.0–15.0 %

Suicide Attempts

Lifetime prevalence 0.4–5.1 % 1.5–12.1 %

Twelve-month prevalence

0.1–3.8 % 1.8–8.4 %

There is considerable cross-national variability in the prevalence of suicidal behaviors.

Three recent cross-national studies use consistent measurement strategies across countries: the WHO/EURO Multicentre Study on Parasuicide the WHO Multisite Intervention Study on Suicidal

behaviors the WHO World Mental Health Survey

All three studies revealed wide cross-national variation in suicidal behaviors.

4. Suicidal behavior cross-nationally Current rates

Our search did not yield any cross-national studies of

trends in suicidal behavior.

Suggest but by no means confirm: there has been no

major change in trends over time.

4. Suicidal behavior cross-nationally Recent trends

The onset and course of suicidal behaviors are quite consistent cross-nationally.

Similar to data in the US. Onset:

The risk of first onset of suicide ideation increases sharply during adolescence and young adulthood and then stabilizes in early midlife.

Course : There is consistency in the timing and probability of

transitioning from suicide ideation to suicide plans and attempts, with 33.6% of ideators going on to make a suicide plan and 29.0% of ideators making an attempt.

4. Suicidal behavior cross-nationally Onset and

course

Demographic factors Suicide: male, an adolescent or older adult, non-Hispanic White or Native

American (in the US) Suicidal behaviors: female, younger, unmarried, having lower educational

attainment, unemployed Psychiatric factors

Mood, impulse-control, alcohol/substance use, psychotic, personality disorders

Psychological factors Hopelessness , anhedonia, impulsiveness , high emotional reactivity

Biologic factors disruptions in the functioning of serotonin

Stressful life events Diathesis-stress model family conflicts, legal problems, child maltreatment

Other factors: access to lethal, chronic or terminal illness,…

5. Risk factors

Protective factors are those that decrease the

probability of an outcome in the presence of

elevated risk.

Religious beliefs, religious practice, and

spirituality

Moral objections to suicide

Social support

Being pregnant and having young children

6. Protective factors

Means-restriction programs: can decrease

suicide rates by 1.5–23%.

Primary-care physician education and training

programs: show reductions of 22–73%.

Although effective prevention programs exist

Many people engaging in suicidal behavior do not

receive treatment of any kind.

7. Prevention/intervention programs

Discussion

Summary of findings First, global estimates suggest that suicide continues to be a

leading cause of death and disease burden and that the number of suicide deaths will increase substantially over the next several decades.

Second, the significant cross-national variability reported in rates of suicide and suicidal behavior appears to reflect the true nature of this behavior and is not due to variation in research methods.

Discussion

Summary of findings Third, there is cross-national consistency in the early age of

onset of suicide ideation, the rapid transition from suicidal thoughts to suicidal behavior, and the importance of several key risk factors.

Fourth, despite significant developments in treatment research and increased use of health-care services among suicidal persons in the United States, there appears to have been little change in the rates of suicide or suicidal behavior over the past decade.

Discussion Research directions Testing theoretical models

diathesis-stress models gene-environment interactions which factors predict transitions from ideation to plans and attempts

Incorporating methodological advances Low base-rate problem

telephone surveys and Web-based surveys Detection of suicidal behavior

computer-based interviews, presenting survey items in written form behavioral methods

Conducting epidemiologic experiments increased use of epidemiologic experiments on prevention and intervention procedures Natural experiments Quasi-experiments True experiments

Comment

US Cross-national China

Suicide

Current rate 10.8/100000 16.7/100000 23/100000

Recent trends decline increase decline

Suicide Behavior

Current rate

Recent trends increase stable

Plentiful resources from government include suicide and suicidal behaviors

Urban-rural differences Compare between US and cross-national and China

Comment

Understanding of variation of suicide rate： Due to difference in measurement methods. Cross-national studies use consistent measurement.

true variation?

Understanding of consistency of suicide trends cross-national