Epidemiology

Suicide Completions

Suicide is very rare before puberty. Rates of completed suicide increase steadily across the teen years and into young adulthood, peaking in the early 20s. Males complete suicide at a rate 4 times that of females and represent 79.4% of all suicides. Firearms remain the most commonly used method of completing suicide for males, whereas females are more likely to complete suicide by poisoning (Fig. 25-1). In the past 60 yr, the suicide rate has quadrupled among 15-24 yr old males and has doubled for females of the same age. The male:female ratio for completed suicide rises with age from 3 : 1 in young children to approximately 4 : 1 in 15-24 yr olds, and to greater than 6 : 1 among 20-24 yr olds.

Figure 25-1 Annual suicide rates among persons aged 15-19 yr, by year and method, United States, 1992-2001.

(From Centers for Disease Control and Prevention: Methods of suicide among persons aged 10–19 years, United States, 1992–2001, MMWR Morb Mortal Wkly Rep 53:471–474, 2004.)

The ethnic groups with the highest risk for completed suicide are American Indians and Alaska Natives. Within this population, suicide is the second leading cause of death, accounting for nearly 1 in 5 deaths among youth ages 15-24 yr. The ethnic groups with the lowest risk are African-Americans, Hispanics, Asians, and Pacific Islanders. The suicide rate among African-American, Hispanic, and other minority males has continued to increase, and the rate among white males has remained steady. Suicide risk also varies in different countries (Fig. 25-2).

Figure 25-2 Suicide rates in selected regions and countries.

(From Hawton K, van Heeringen K: Suicide. Lancet 373:1372–1380, 2009.)

Suicide Attempts

It is estimated that for every completed youth suicide, as many as 200 suicide attempts are made. Ingestion of medication is the most common method of attempted suicide. The 15 to 19 yr old age group is the most likely to intentionally harm themselves by ingestion, receive treatment in emergency departments, and survive. Attempts are more common in girls than boys (approximately 3 : 1), and in Hispanic girls than their non-Hispanic white or non-Hispanic African-American counterparts. Gay, lesbian, and bisexual youths are also at increased risk for suicide attempts. Suicide attempts among African-American adolescent males have more than doubled from 1991 to 2001. Attempters who have made prior suicide attempts, who used a method other than ingestion, and who still want to die are at increased risk for completed suicide.

Suicide Ideation

Based on the 2007 Youth Risk Behavior Survey, 14.5% of students in grades 9 through 12 reported that they had seriously considered attempting suicide in the 12 mo preceding the survey (18.7% of females and 10.3% of males). Nearly 7% of students reported that they had actually attempted suicide at least once during the same period.

Risk Factors

In addition to age, race and ethnicity, and a history of a previous suicide attempt, there are multiple risk factors that predispose youths to suicide.

Pre-existing Psychiatric Illness

The great majority (estimated at 90%) of youths who complete suicide have a pre-existing psychiatric illness, most commonly major depression (Chapter 24.1). Among girls, chronic anxiety, especially panic disorder, also is associated with suicide completion (Chapter 23). Among boys, conduct disorder and substance use convey increased risk. Comorbidity of a substance use disorder (Chapter 108), a mood disorder (Chapter 24), and conduct disorder (Chapter 27) has been linked to suicide by firearm.