Understanding the development of non-suicidal self-injury during adolescence

Up to 40% of Swedish adolescents report deliberately harming themselves (e.g., cutting or burning themselves), without intending suicide.

The aim of this project is to strengthen prevention efforts through understanding the ways that this self-injury changes during adolescence.

Understanding whose self-harm increases and whose decreases during adolescence is important because it tells us when to apply prevention/intervention efforts and who needs these efforts the most.

Presently, such information does not exist because the studies that have multiple assessments are over short periods of time or lack the breadth of measurement needed. We need multiple assessments over the whole period of adolescence, with relevant risk factors assessed in one dataset.

Fortunately, such data were collected recently in Sweden.These data, from the 3 Cities Study (2013-2018), are unique in several ways. First, the data include five annual assessments of the same adolescents. With a sample of over 3000 students, the data are optimal for identifying different paths of change.

Second, the data include reports from adolescents and their parents, as well as from their friends.

Friends’ data is exceedingly rare and important for estimating the degree to which friends’ influence adolescents’ behavior.

We will capitalize on this strength by examining processes of contagion and resistance between adolescents and their friends.

Third, the data contain a broad array of measures tapping individual characteristics and interpersonal processes that include potential risk factors for self-injury, as well as some factors that may reduce risk. With these data, we can address questions of what prompts desisting and what instigates escalation of self-injury.

Answers to such questions are vital for informing prevention and intervention efforts for adolescents.