| William J. Mayo (1861–1939) stated that “the aim of medicine is to prevent disease and prolong life; the ideal of medicineis to eliminate the need of a physician” (1). Hence, physicians have been trying for almost a century to find early interventions that would prevent the onset of diseases, or at least change their course. Big steps have been made in several fields of medicine, such as cardiology and oncology.When it comes to psychiatry, although there is ground for optimism, there is still a long way to go (2). Difficulties concerning primary prevention and intervention in psychiatry arise mainly from the absence of a clear etiology. Consequently, psychiatry has focusedmore on tertiary prevention, that is, in the use of therapies aiming to minimize theconsequences of clinicallyestablished disease rather than to prevent its occurrence (3). However, considering the high prevalence of mental illnesses, their significant contribution to global disease burden among young people, and their considerable impact on public health, the implementation of early interventions in psychiatry should be considered a major priority. To achieve this goal, and since early intervention focuses on known risk factors and early signs of the illness, there is a growing interest in understanding the early course of psychiatric conditions. For bipolar disorder, until recently most information regarding early manifestations came from retrospective and cross-sectional studies, which have a high risk of recall bias and do not allow assessment of temporality. Still, current evidence suggests that bipolar disorder has a progressive nature (4–6), therefore supporting the existence of milder phases of the condition prior to the classic presentation of the illness. This progressive nature makes bipolar disorder an ideal candidate for early intervention strategies, especially considering that 50%270% of people with bipolar disorder usually start to manifest mood symptoms before age 21 (7–12). This highlights the need for earlyinterventions to prevent or atleast delay the onset of the full syndromal illness during childhood, which is crucial to avoid impacts on normal developmental tasks and psychosocial or neurobiological deterioration (13) and to prevent future complications, such as the development of psychiatric comorbidities, impaired functioning, or premature death by suicide (14). |