Childhood Adversities Associated With Risk for Suicidal Behavior

It has been estimated that worldwide almost a million persons commit suicide every year.¹ In the United States, the annual suicide rate is approximately 12 per 100,000.² In Europe, the suicide rate ranges from approximately 4 per 100,000 (Greece, Italy, Spain) to 40 per 100,000 (Hungary, Finland, Sweden).³ Intermediate suicide rates such as 22 per 100,000 have been reported in other nations (eg, China).⁴ The most common immediate risk factors for suicide are mental disorders, particularly mood and substance use disorders. Almost 90% of suicide attempts take place among persons with a current mental disorder; and approximately 80% of these persons do not receive treatment before attempting suicide.^5,6 Other suicide risk factors include chronic pain or psychiatric disorder of one's partner.^7,8

Suicide rates increased in many parts of the world from 1970 to 1990, followed by a plateau or a slight decrease in recent years.^9,10 Suicide is relatively rare among children younger than 10 years (0.05 cases per 100,000). In early adolescence (10 to 14 years), there is a 30-fold increase in risk (approximately 1.5 cases per 100,000). Among 15- to 24-year-olds, an additional 10- fold rise in risk has been observed (13 cases per 100,000).¹¹ Although women report more suicide attempts and suicidal ideation, men have the highest rate of completed suicide.^12,13

Epidemiology of severe childhood adversities

Documented cases of childhood physical abuse, sexual abuse, and neglect are relatively common in the general population (approximately 12 victims per 1000 children). In 2004, an estimated 872,000 children were found to be victims of childhood abuse or neglect in the United States.¹⁴ Because many cases of abuse and neglect are not reported to authorities, the actual frequency of childhood maltreatment is likely to be substantially higher.¹⁵ Physical punishment during childhood is common (approximately 60% of adults in the United States report having experienced corporal punishment in childhood). More severe acts of physical violence and victimization during childhood (eg, being struck with objects) were reported by 11% of adults in 1985; the prevalence of childhood physical abuse was estimated to be 1.9% in 1985.

The prevalence of sexual abuse was investigated in a recent meta-analysis of 168 studies including almost 1 million persons.¹⁶ Worldwide, about 5% of women and 3% of men reported having been sexually abused during childhood (intercourse or anal/oral contact). An additional 13% of women and 3% of men reported less severe incidents of sexual activity (unwanted physical contact without intercourse or anal/oral contact). Moreover, 7% of women and 3% of men reported incidents of childhood sexual abuse without physical contact, such as exhibitionism.

Specific childhood adversities associated with risk for suicidal behavior

Numerous studies have investigated the associations of specific childhood adversities with suicide risk. These adversities include childhood maltreatment, problematic family relationships, socioeconomic hardship, and difficult relationships with peers (Table).^17-28 Childhood physical and sexual abuse have been found to be particularly important risk factors in retrospective^29-30 and prospective studies^31,32 in populations of young adults²⁰ and older adults.³³ Problematic family relationships, including certain combinations of maladaptive parental behaviors (eg, affectionless or overprotective parenting), have been reported to be associated with risk for suicide.^34-36

Other risk factors include a history of mental disorders,⁹ parental psychopathology,³⁷ a family history of suicidal behavior,¹⁷ and parental financial hardship or unemployment.²¹ Suicidal behavior is known to be multidetermined, with many risk factors playing important contributory roles.^9,21,38 For example, one study showed that of 70 risk factors investigated in bivariate analyses, more than 50 were significantly associated with suicidal ideation or deliberate selfharm. ³⁹ In addition, persons who have experienced a series of adversities during childhood and adolescence have been found to be at particularly elevated risk for suicide.^35,40

Several studies have examined a variety of risk factors and their differential contributions to later suicide risk. Studies using cumulative adversity indices have indicated that the predictive power for single adversities was lower than for the combined effects of multiple risk factors.^29,38 The underlying rationale of the use of summation indices is that most persons are resilient enough to cope with a certain amount of adversity, but if adversities rise above this threshold, coping abilities fail and risk for suicidal behavior increases.^21,41 When extreme groups are compared, this can result in extraordinarily large effect sizes. For example, Felitti and associates²⁹ found that there was a 25-fold increase in the probability of reporting a suicide attempt by persons who reported numerous childhood adversities compared with persons who reported only one risk factor or none at all.⁴²