Mild-to-moderate disorders are typically understood not to require highly specialised treatments delivered by psychiatrists or in inpatient settings in the vast majority of cases. Instead, in most OECD countries primary care practitioners take a leading role in treating mild-to-moderate disorders (see Table 4.2). When primary care-level provision for mild-to-moderate disorders is backed up by good training (both during medical training and as part of Continuing Medical Education), by support from specialist mental health care practitioners and support networks, and by good referral options should a patient need to access a more specialised level of care, it can be a highly effective way of delivering care to a large number of patients.