Editorial: 'The early bird catches the worm'-the need for even earlier intervention and targeted prevention for mental illnesses.

Intervening early during childhood and adolescence to prevent mental health problems from becoming chronic, or even to prevent them occurring at all, has become an increasingly popular approach within the field of mental health over the past three decades. The importance of, and potential for, early preventive interventions in infancy, the pre-natal period and even pre-conception is highlighted by several of the papers featured in the current issue of the Journal, which are summarised in this editorial. Identifying children most at risk of mental illness in order to selectively target preventive efforts and carefully testing the effectiveness of these interventions, particularly in low-and middle-income country contexts, are crucial next steps as we move towards an era of more personalised and earlier prevention and intervention in mental health.