Background
Depressive, anxiety
DISORDERS
Depressive and anxiety disorders are 2 of the most common mental health difficulties, with epidemiological studies across countries suggesting that they are highly prevalent, can persist throughout lifetime, and are seriously impairing [A key value in digitally delivered treatments is the ability to collect data on patient characteristics, routine outcome measures, and their engagement with the intervention. Given the volume of data collected, there is a potential new opportunity to understand treatment effects at an individual level. More than ever before, we can understand the trajectory of individual symptom changes and further explore the relationship between the use of the intervention and clinical outcomes. Understanding treatment effects over time and the relationship between use and outcomes may prove important for developing tailored interventions for different [Most empirical evidence on trajectories of symptom change comes from face-to-face psychotherapy studies, which have found various classes of symptom courses, from early responders to late or delayed responders and steady or moderate responders [In terms of intervention use and its relationship with outcomes from iCBT [