The social contagion effect of suicidal behavior in adolescents: does it really exist?

Suicide is the third leading cause of death among adolescents and a non-trivial percentage of adolescents report knowing someone who has attempted suicide. In light of this, a growing body of literature has explored whether suicidal behavior in one person may be imitated by others in their social networks.

We seek to determine the extent to which suicidal behavior in individuals is influenced by suicidal behaviors of their peer and family members.

Using a nationally-representative sample of adolescents, we employ multivariate regression analysis with controls for known factors associated with suicidal behaviors to help isolate the effects of peer and family members on suicidal behaviors. Our methodology allows us to account for environmental confounders, simultaneity and to a limited extent, non-random peer selection. Our peer measures are drawn from the nomination of close friends by the individuals and suicidal behaviors among the peer group were constructed using the peers' own responses.

We find that a 10% increase in suicide attempts by family members were associated with a 2.13% and 1.23% increase in adolescent suicidal ideation and attempts, respectively. Our results also show that a 10% increase in peer suicidal ideation and attempts lead to a 0.7% and 0.3% increase in such behavior by the individuals. However, these positive associations between peer and individual suicide behavior become smaller and insignificant after adjustments were made for environmental confounders and peer selection.

Although we are able to establish the overall importance of environmental confounding factors, we are unable to identify the specific components or characteristics of the surroundings that can explain suicidality. The complex relationships between peer selection and suicidality also limit the determination of causality.

An increase in suicidal behavior by family members is positively associated with suicidal behavior among adolescents and effective policies aimed at reducing suicidal rates should consider these impacts. However, attributing correlations in suicidal behaviors among peers to social network effects should be undertaken with caution, especially when environmental confounders are not adequately controlled for in the analysis.

Recent studies have found evidence that family connectedness and parent-child relationships have a significant impact in deterring risky behaviors among adolescents. This motivates future work aimed at designing policies that would utilize these findings in order to effectively reduce suicidal behavior among adolescents.