Depression, impulsivity, and aggression during adolescence have been associated with both adoption and suicidal behavior. Studies of adopted adults suggest that impulsivity, even more than depression, may be an inherited factor that mediates suicidal behavior. However, the association between adoption and adolescent suicide attempts and the mechanisms that might explain it remain unknown. The objective of this study was to determine the following: 1) whether suicide attempts are more common among adolescents who live with adoptive parents rather than biological parents; 2) whether the association is mediated by impulsivity, and 3) whether family connectedness decreases the risk of suicide attempt regardless of adoptive or biological status.
A secondary analysis of Wave I data from the National Longitudinal Study of Adolescent Health was conducted, which used a school-based, clustered sampling design to identify a nationally representative sample of 7th- to 12th-grade students, with oversampling of underrepresented groups. Of the 90 118 adolescents who completed the National Longitudinal Study of Adolescent Health in-school survey, 17 125 completed the in-home interview and had parents of identified gender who completed separate in-home questionnaire. The subset of adolescents for this study was drawn from the in-home sampling according to the following criteria: 1) adolescent living with adoptive or biological mother at the time of the interview, 2) adolescent had never been separated from mother for more than 6 months, 3) mother was in first marriage at the time of the interview, and 4) the adoptive mother had never been married to the adolescent's biological father. Of the 6577 adolescents in the final study sample, 214 (3.3%) were living with adoptive mothers and 6363 (96.7%) were living with biological mothers.
The primary outcome measured was adolescent report of suicide attempt(s) in the past year. Other variables included in the analyses were sociodemographics characteristics (gender, age, race/ethnicity, family income, parental education), general health (self-rated health, routine examination in the past year, need for medical care in the past year that was not obtained), mental health (depressive symptoms, self-image, trouble relaxing in the past year, bad temper, psychological or emotional counseling in the past year), risk behaviors (cigarettes, alcohol, marijuana, sexual intercourse ever, delinquency, physical fighting in the past year, impulsive decision making), school-related characteristics (grade point average, school connectedness), and family interaction (family connectedness, parental presence, maternal satisfaction with parent–adolescent relationship).
Univariate analyses were used to compare adoptees versus nonadoptees, suicide attempters versus nonsuicide attempters, and adopted suicide attempters versus nonadopted suicide attempters on all variables. Variables that were associated with attempted suicide were entered into a forward stepwise logistic regression procedure, and variables that were associated with the log odds of attempt were retained in the model. The area under the model's receiver operating characteristic curve was calculated as a measure of its overall performance. After the association of adoption with attempted suicide was demonstrated, the potential mediating effect of impulsivity was explored by adding it to the model. The same procedure was followed for any variable that was associated with adoption in the full sample or the subsample of suicide attempters. To determine whether any variable in the model moderated the association between adoption and suicide attempt, the interaction term for that variable × adoption was forced into the model.
Adoptees differed significantly from nonadoptees on 4 of 26 variables. They were more likely to have attempted suicide (7.6% vs 3.1%) and to have received psychological or emotional counseling in the past year (16.9% vs 8.2%), and their mothers reported higher parental education and family income. Attempters differed significantly from nonattempters on all variables except for age, race/ethnicity, parental education, family income, and routine examination in the past year. On logistic regression, 9 variables were independently associated with attempted suicide: depression (adjusted odds ratio [AOR]: 3.41), counseling (AOR: 2.83), female gender (AOR: 2.31), cigarette use (AOR: 2.31), delinquency (AOR: 2.17), adoption (AOR: 1.98), low self-image (AOR: 1.78), aggression (AOR: 1.48), and high family connectedness (AOR: 0.60). The receiver operating characteristic curve for the model had an area of 0.834, indicating performance significantly better than chance. The AOR for adoption did not change when parental education, family income, and impulsivity were forced into the model. None of the interaction terms (adoption × another risk factor) demonstrated a significant effect.
Attempted suicide is more common among adolescents who live with adoptive parents than among adolescents who live with biological parents. The association persists after adjusting for depression and aggression and is not explained by impulsivity as measured by a self-reported tendency to make decisions quickly. Although the mechanism underlying the association remains unclear, recognizing the adoptive status may help health care providers to identify youths who are at risk and to intervene before a suicide attempt occurs. It is important to note, however, that the great majority of adopted youths do not attempt suicide and that adopted and nonadopted youths in this study did not differ in other aspects of emotional and behavioral health. Furthermore, high family connectedness decreases the likelihood of suicide attempts regardless of adoptive status and represents a protective factor for all adolescents.