Co-development of anxiety and depression in UK and Brazil youth; a cross-country comparison

The study examined how anxiety and depression develop together in children and adolescents in the United Kingdom (9,586 participants) and Brazil (3,815 participants) from early childhood to adolescence. The prevalence of both disorders was similar across both countries. Researchers identified four developmental trajectory classes: stable-low (41% in UK, 54% in Brazil), increasing (31% and 28%), decreasing (23% and 15%), and persistent-high anxiety with increasing depression (5% and 3%). Young people in the increasing or persistent-high symptom classes had significantly elevated risk of depression and anxiety in adulthood compared to the stable-low class. In Brazil, anxiety increased more rapidly than in the UK, which may reflect country-specific risk factors. The results suggest that patterns of co-development are comparable across both countries and that persistence or emergence of symptoms beyond early childhood is critical for identifying later diagnostic risk.