The study looked at a community sample of 169 adolescents over 10 years, from the time they were aged 15 to when they were 25. The youth were racially, ethnically and socio-economically diverse. Adolescents were assessed annually, answering questions about who their closest friends were, reporting on their friendships and participating in interviews and assessments exploring such feelings as anxiety, social acceptance, self-worth and symptoms of depression.