THE ARTICLE by Judd et al1 from the Collaborative Program on the Psychobiology of Depression from the National Institute of Mental Health (Bethesda, Md) confirms and extends earlier longitudinal work on the synchrony of change in depression severity and level of psychosocial disability. These earlier naturalistic studies2-4 found that disability was reduced among patients in primary care whose depressive and anxiety disorders improved, while, in contrast, patients whose psychological illness ran a chronic course maintained elevated disability levels 1 to 3 years later. Judd et al now show that the synchrony of change in depression severity and level of disability remains at the within-subject level over 10 years on average. Increments in depressive symptom severity were associated with increments in disability, and reductions in depressive symptom severity were associated with reductions in disability. What is new and exciting in their work is the combination of monthly assessments of symptoms and psychosocial functioning over an extended period with the application of recently developed advanced statistical methods, which comprise the so-called random regression model.