Self-Destructive Behaviors:Definitions & Rates

Prof. Matthew K. Nock

Why Study Self-Injurious Behaviors?

“There is but one truly serious philosophical problem, and that is suicide. Judging whether life is or is not worth living amounts to answering the fundamental question of philosophy. All the rest– whether or not the world has three dimensions, whether the mind has nine or twelve categories– comes afterwards. These are games; one must first answer.”

--Albert Camus, The Myth of Sisyphus

Why Study Self-Injurious Behaviors?

• ~1 million suicide deaths annually; 1 every 40 seconds

• ~30,000 deaths each year in US

• Twice as many suicides as HIV/AIDS deaths, >homicides

• 11th leading cause of death, 3rd among adolescents

• 15% of high school students “seriously consider” suicide, and 7% make a suicide attempt (YRBS, 2007)

• 97% of clinical psychology students see ≥ 1 suicidal patient;

25% of psychologists and 50% of psychiatrists lose patient to suicide (Kleespies & Dettmer, 2000)

Public Health Context

Country Year Males Females

Ukraine 2000 52.1 10.0

Japan 2000 35.2 13.4

Belgium 1997 31.2 11.4

France 1999 26.1 9.4

Bulgaria 2002 25.6 8.3

Romania 2002 23.9 4.7

China 1999 13.0 14.8

Germany 2001 20.4 7.0

Australia 2001 20.1 5.3

Ireland 2000 20.3 4.3

New Zealand 2000 19.8 4.2

India 1998 12.2 9.1

United States 2000 17.1 4.0

Netherlands 2000 12.7 6.2

Spain 2000 13.1 4.0

Suicide Rates (per 100,000) by Country: WHO 2005

Country Year Males Females

Italy 2000 10.9 3.5

Israel 1999 9.8 2.3

Costa Rica 1995 9.7 2.1

Brazil 1995 6.6 1.8

Panama 1987 5.6 1.9

Colombia 1994 5.5 1.5

Mexico 1995 5.4 1.0

Peru 1989 0.6 0.4

Indonesia -- -- --

Nigeria -- -- --

South Africa -- -- --

Turkey -- -- --

Suicide Rates (per 100,000) by Country: WHO 2005

U.S. Suicide Rate by Age, Gender & Race

U.S. Suicide Rate by Age, Gender & Race

U.S. Suicide Rate by Age & Sex Over Time

U.S. Suicide Rate by Region

U.S. Suicide Rate by Age, Gender & Race

U.S. Suicide Rate by Age, Gender & Race

U.S. Suicide Rate by Age, Gender & Race

U.S. Suicide Rate by Age, Gender & Race

U.S. Suicide Rate by Method & Gender

Death Rates of U.S. Youth

Suicide Rates by Month

Current Context

• Suicide & NSSI are very difficult to predict & prevent

Classifying Self-Injurious Thoughts and Behaviors

• Common terms: “suicidality” …“deliberate self-harm”… “parasuicide”…

• More specific terms and definitions:

– Suicide ideation: thoughts of intentionally ending one’s own life

– Suicide plan: selection of method with some intent to act in the future

– Suicide attempt: self-injurious behavior with intent to die

– Non-suicidal self-injury (NSSI): self-injury with no intent to die

Nock & Kessler (2006) J Abnormal Psychology

Nock & Kazdin (2002) J Clinical Child & Adolescent Psychology

Epidemiology of Suicidal Outcomes

• What is the prevalence of suicide ideation, plans, and attempts?• What are the onset, course, and risk factors?

Epidemiology of Suicidal Outcomes

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Epidemiology of Suicidal Outcomes

• What is the prevalence of suicide ideation, plans, and attempts?• What are the onset, course, and risk factors?

• WHO World Mental Health Survey Initiative (Kessler et al):

nationally representative survey in 28 countries (N ~ 250,000)

Prevalence

Estimate Range

Suicide Ideation 9.2% (3.1China - 15.9New Zealand)

Suicide Plan 3.1% (0.7Italy - 5.6New Zealand)

Suicide Attempt 2.7% (0.9Italy - 5.0USA)

Nock et al. (2008). British Journal of Psychiatry

N = 84,850; 17 Countries

Epidemiology of Suicidal Outcomes

• Although variability in prevalence of suicidal outcomes, there is consistency in:– Age-of-onset (AOO) of suicidal outcomes

Nock et al. (2008). British Journal of Psychiatry

Epidemiology of Suicidal Outcomes

Nock et al. (2008). British Journal of Psychiatry

Epidemiology of Suicidal Outcomes

• Although variability in prevalence of suicidal outcomes, there is consistency in:– Age-of-onset (AOO) of suicidal outcomes

– Conditional probabilities of transition from ideation to plans (33.6%) and attempts (29.0%)

– Speed of transition from ideation to plans and attempts

Nock et al. (2008). British Journal of Psychiatry

Epidemiology of Suicidal Outcomes

Nock et al. (2008). British Journal of Psychiatry

Epidemiology of Suicidal Outcomes

• Although variability in prevalence of suicidal outcomes, there is consistency in:– Age-of-onset (AOO) of suicidal outcomes

– Conditional probabilities of transition from ideation to plans (33.6%) and attempts (29.0%)

– Speed of transition from ideation to plans and attempts

– Risk factors for suicide ideation, plans, and attempts• Female, younger age, unmarried• Presence of mental disorders

Nock et al. (2008). British Journal of Psychiatry

Epidemiology of Suicidal Outcomes

Nock et al. (2008). British Journal of Psychiatry

Predictors of Transition from Suicide Ideation to Attempt

Nock et al. (2010). Molecular Psychiatry (US)

Nock et al. (2009). PLoS Medicine (Cross-nationally)

Prediction of first onset of suicide ideation and attempts in the NCS-R

Suicide

Ideation

Attempts among

Ideators

Depression (MDD)

Anxiety (PTSD)

Conduct (CD)

Alcohol (Abuse/Dep)

…Values are ORs from multivariate survival models predicting ideation in the total sample (column 1), and unplanned attempts among ideators (column 2) in the NCS-R. Models included 16 disorders– only 4 shown here.

Predictors of Transition from Suicide Ideation to Attempt

Prediction of first onset of suicide ideation and attempts in the NCS-R

Suicide

Ideation

Attempts among

Ideators

Depression (MDD) 2.3*

Anxiety (PTSD) 1.5*

Conduct (CD) 1.5*

Alcohol (Abuse/Dep)

…

1.8*

Values are ORs from multivariate survival models predicting ideation in the total sample (column 1), and unplanned attempts among ideators (column 2) in the NCS-R. Models included 16 disorders– only 4 shown here.

Nock et al. (2010). Molecular Psychiatry (US)

Nock et al. (2009). PLoS Medicine (Cross-nationally)

Predictors of Transition from Suicide Ideation to Attempt

Prediction of first onset of suicide ideation and attempts in the NCS-R

Suicide

Ideation

Attempts among

Ideators

Depression (MDD) 2.3* 1.0

Anxiety (PTSD) 1.5* 2.4*

Conduct (CD) 1.5* 2.2*

Alcohol (Abuse/Dep)

…

1.8* 2.9*

Values are ORs from multivariate survival models predicting ideation in the total sample (column 1), and unplanned attempts among ideators (column 2) in the NCS-R. Models included 16 disorders– only 4 shown here.

Nock et al. (2010). Molecular Psychiatry (US)

Nock et al. (2009). PLoS Medicine (Cross-nationally)

Self-Injury Rate by Sex

Self-Injury Rate Over Time

Rate of NSSI among U.S. Youth

(Hilt, Nock, Lloyd-Richardson & Prinstein, 2008)

Percentage of preadolescents who reported engagement in NSSI (N = 508)

7.7 6.5 8.9 7.6 1016.7

7.7 6.6 7.3 9.3

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Self-Destructive Behaviors:Definitions & Rates

Prof. Matthew K. Nock