Early substance misuse continues into middle age

In the present thesis, Yasmina Molero Samuelson has followed two large cohorts of adolescents for several decades. These cohorts received treatment for substance misuse at a clinic in Stockholm, Sweden during two time periods; the end of the 1960s, and the beginning of the 1980s. The cohorts were followed until 2002, and were compared to two matched samples from the general population. Approximately 7,000 individuals were included in the studies.

The results demonstrate that adolescents treated for substance misuse, as compared to the individuals in the matched sample, to a significantly greater degree experienced psychosocial problems long after the end of the treatment, even up to age 50. They also demonstrated a greater risk of experiencing several concurrent problems as adults.

The thesis also shows that there were more similarities than differences among males and females who received treatment for their substance misuse as adolescents. For example, females with delinquency and substance misuse problems exhibited an equal risk of developing psychosocial problems in adulthood as their male counterparts. Furthermore, a considerable number of the females who were treated at the clinic committed crimes, both in adolescence and in adulthood. Across gender, the crimes included non-violent crimes, violent crimes, and substance-related crimes.

"What we can see is that adolescent antisocial behavior, manifested through substance misuse and delinquency significantly increases the risk of various types of psychosocial problems in adulthood, even into middle age", says Yasmina Molero Samuelson. "This emphasises the importance of early and effective interventions in order to prevent a negative development that risks being maintained for the most part of a person's life."

The breadth of problems experienced in adulthood suggests that interventions for adolescents in treatment settings should not focus solely on the substance misuse or delinquency; it is equally important to assess and treat problems in other areas as well.

"The results also clearly show the importance of not overlooking young girls in this these types of contexts, since they too demonstrate severe antisocial behaviour, and are equally at risk of developing problems throughout their lives as their male counterparts", says Yasmina Molero Samuelson.

More information: Antisocial behavior over the life course among females and males treated for substance misuse. ISBN: 978-91-7457-064-9 Department of Clinical Neuroscience, Karolinska Institutet,

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