摘要：Objectives. We investigated the relationship between friendships and suicidality among male and female adolescents. Methods. We analyzed friendship data on 13 465 adolescents from the National Longitudinal Survey of Adolescent Health to explore the relationship between friendship and suicidal ideation and suicide attempts. We controlled for known factors associated with suicidality. Results. Having had a friend who committed suicide increased the likelihood of suicidal ideation and attempts for both boys and girls. Socially isolated females were more likely to have suicidal thoughts, as were females whose friends were not friends with each other. Among adolescents thinking about suicide, suicide attempts appear largely stochastic, with few consistent risk factors between boys and girls. Conclusions. The friendship environment affects suicidality for both boys and girls. Female adolescents’ suicidal thoughts are significantly increased by social isolation and friendship patterns in which friends were not friends with each other. Although suicide rates for most subpopulations tend to be stable over time, the suicide rate among adolescents has risen dramatically in recent years. Suicide is now the third leading cause of death among adolescents and young adults aged 15 to 24 years. 1 Although only 1 in 200 suicide attempts results in death, more than one third of all suicide attempts result in injuries serious enough to require professional treatment. Four percent of American adolescents reported at least 1 attempted suicide in the past year, and 13% of adolescents had seriously considered suicide at least once in the past year. 2 The broader impact of suicide on adolescents is substantial. Twenty percent of adolescents reported knowing a friend who had attempted suicide in the past year, and 60% reported knowing a teenager who had ever attempted suicide. 2, 3 Because of this prevalence, it is critical that we understand the determinants of adolescent suicidality for effective identification of adolescents at risk. Many of the basic risk factors for adolescent suicidality are well known; among these, the most important are depression, 2, 4– 6 exposure to suicide or suicide attempts by family or friends, 7, 8 substance or alcohol abuse, 9 and having guns in the home. 2, 10, 11 Furthermore, in light of the differential rates of suicidal ideation and suicide attempts for adolescent males and females, some studies have suggested different etiologies for girls and boys. 6, 9, 12– 14 However, most of the previous studies of adolescent suicide have relied on small samples of psychiatric inpatients, 4, 15 case–control designs, 16, 17 or autopsy studies of completed suicides. Few longitudinal population-based studies have examined risk factors from multiple domains. We used data from a nationally representative sample of adolescents in the United States and examined the relative importance of various risk factors associated with both suicidal ideation and suicide attempts. In addition to measuring previously identified risk factors, we assessed the potential role that friendship patterns play in shaping adolescent suicidality. Because our sample was large, we were able to compare the patterns of risks for boys and girls separately and to model the risks of both suicidal thoughts and suicide attempts. Adolescent well-being is largely the product of interactions among the multiple contexts in which adolescents are embedded. 2 Central contexts for adolescents include family, school, friendships, romantic relationships, peer groups, and larger social networks. The National Longitudinal Study of Adolescent Health (Add Health) provides unique data on adolescents’ relationships with their friends, in that it is the only national level data set to provide information on network structure. These data allow for measurement of adolescent social network position, the quality of adolescents’ social relations with peers, and the structural position adolescents occupy in the adolescent social world. Bearman 18 suggested that adolescent suicidality may be a product of network positions characterized by either relative isolation or structural imbalance (Moody J, unpublished data, 1999), and a growing body of research links social isolation to suicide. 18, 19 Researchers have known for some time that isolation from peers leads to lower estimations of self-worth and self-confidence. 22, 23 We examined 2 individual-level network factors. First, isolated adolescents have few or no ties to the remainder of the school. Students in such positions may internalize isolation as low self-worth and may be more likely to consider suicide. This hypothesis follows directly from Bearman’s extension of Durkheim 18, 24 and previous evidence concerning sense of self. 22 Second, cultural pressures for social balance, 25 particularly among youths, 26, 27 suggest that one’s friends should be friends with each other. Adolescents whose friends are not friends with each other are subject to competing normative pressures that lower effective normative regulation and increase suicidal ideation. 22 For the school as a whole, communities with many relations provide stronger moral integration and greater opportunities for monitoring, which likely results in lower suicidal ideation and suicide attempts, respectively.
