The increased prevalence of emotional problems in girls mirrors a trend found in other similar studies, and the results are discussed in the context of recent economic and societal changes. The small decrease in total difficulties in boys, although promising, clearly warrants further research.

Due to recent increases in the use of feedback from outcome measures in mental health settings, we systematically reviewed evidence regarding the impact of feedback from outcome measures on treatment effectiveness, treatment efficiency, and collaborative practice. In over half of 32 studies reviewed, the feedback condition had significantly higher levels of treatment effectiveness on at least one treatment outcome variable. Feedback was particularly effective for not-on-track patients or when it was provided to both clinicians and patients. The findings for treatment efficiency and collaborative practice were less consistent. Given the heterogeneity of studies, more research is needed to determine when and for whom feedback is most effective.

Chronic friendlessness in childhood predicts adverse mental health outcomes throughout life, yet its earliest roots are poorly understood. In theory, developing a theory of mind (ToM) should help children gain mutual friends and one preschool study (Peterson & Siegal, 2002. Br J Dev Psychol, 20, 205) suggested a cross-sectional connection. We therefore used a 2-year prospective longitudinal design to explore ToM as a predictor of mutual friendship in 114 children from age 5 to 7 years after controlling potential confounds including language ability and group popularity. Confirming friendship's distinctiveness from group sociometric status, numerous group-rejected children (53%) had a mutual friend whereas 23% of those highest in group status did not. Five-year-olds with a mutual friend significantly outperformed their friendless peers on a comprehensive ToM battery (basic and advanced false belief). Longitudinally, chronically friendless 7-year-olds (no friends at either testing time) stood out for their exceptionally poor Time 1 ToM understanding even after controlling for group popularity, age, and language skill. Extending previous evidence of ToM's predictive links with later social and cognitive outcomes, these results for mutual friendship suggest possible interventions to help reduce the lifelong mental health costs of chronic friendlessness.